@article{babar_harrison_blount_barnett_johnson_mergoum_mailhot_murphy_mason_shakiba_et al._2024, title={Registration of 'FL12034-10' oat: A new dual-purpose disease resistant cultivar for Florida and southern United States}, ISSN={["1940-3496"]}, DOI={10.1002/plr2.20362}, abstractNote={Abstract‘FL12034‐10’ (Reg. no. CV‐389, PI 704483), a facultative oat (Avena sativa L.) cultivar, co‐developed by the University of Florida and Louisiana State University Agricultural Center, was released in October 2022. FL12034‐10 was derived from a three‐way cross LA06055SBSBSB‐79/FL11048 F1. It is well adapted across the southern United States and provides producers with a medium‐tall, mid‐season, awnless, white‐glumed, dual‐purpose oat that has high yield potential, good straw strength, and good forage yield. FL12034‐10 was observed to be uniform and stable across environments in the southern United States from 2017 to present. The line possesses a semi‐prostrate growth habit, vigorous growth, and high tillering capacity, and has large leaves that are dark green in color. It expresses moderate‐to‐high levels of resistance to most oat diseases prevalent in the southern United States. The crown and stem rust and Barley yellow dwarf virus ratings (0–9 scale) of FL12034‐10 were 1.7, 0.7, and 1.5, respectively, across different environments. The disease ratings were better than most of the checks. The grain yield average of FL12034‐10 from 41 environments during 2018–2021 was 6437 kg ha−1, which is competitive with check cultivars that are widely used in the southern part of the United States. The forage yield of FL12034‐10 ranged from 2358 to 6617 kg ha−1 (20 environments), which was higher than most of the checks. FL12034‐10 demonstrated better lodging and disease resistance, higher grain yield potential, and higher mid‐winter to late spring season forage yield potential than Horizon 720 and Legend 567 oats released by University of Florida.}, journal={JOURNAL OF PLANT REGISTRATIONS}, author={Babar, Md Ali and Harrison, Stephen A. and Blount, Ann and Barnett, Ronald D. and Johnson, Jerry and Mergoum, Mohamed and Mailhot, Daniel J. and Murphy, J. Paul and Mason, Richard E. and Shakiba, Ehsan and et al.}, year={2024}, month={Apr} } @article{babar_harrison_blount_barnett_johnson_mergoum_mailhot_murphy_mason_ibrahim_et al._2023, title={'FLLA09015-U1': A broadly adapted dual-purpose oat cultivar for southern USA}, ISSN={["1940-3496"]}, DOI={10.1002/plr2.20249}, abstractNote={Abstract‘FLLA09015‐U1’ (Reg. no. CV‐387, PI 699117) is a new facultative oat (Avena sativa L.) cultivar that was co‐developed by the University of Florida and Louisiana State University Agricultural Center and was released in 2019. This line was derived from a single cross of FL0210‐J1/MN06203. FLLA09015‐U1 has considerable potential for grain and forage yield and for conservation tillage purposes in the southern United States. Exclusive marketing rights for FLLA09015‐U1 has been granted to JoMar Seeds and is currently commercialized under the name of Juggernaut. FLLA09015‐U1 was developed using selected bulk breeding method and was selected as an F5:6 head row. The line was evaluated in advanced, regional, and state grain and forage yield trials from 2015 to 2021. FLLA09015‐U1 was observed to be uniform and stable across environments in the southern United States from 2015 to present. The line possesses a semi‐prostrate growth habit and has large leaves that are dark green in color. It is a mid‐maturing, medium to mid‐tall height with excellent grain yield and good forage yield and test weight. It has excellent crown rust resistance and very good resistance to Barley yellow dwarf virus and stem rust and demonstrated moderate lodging resistance. It has performed very well in both grain and forage trials. FLLA09015‐U1 has broad environmental adaptation and has performed well in Louisiana, Florida, Georgia, Texas, Alabama, and South Carolina. We consider FLLA09015‐U1 to be a good dual‐purpose type of oat because of its high grain yield potential and vigorous growth and high tillering capacity.}, journal={JOURNAL OF PLANT REGISTRATIONS}, author={Babar, Md Ali and Harrison, Stephen A. and Blount, Ann and Barnett, Ronald D. and Johnson, Jerry and Mergoum, Mohamed and Mailhot, Daniel J. and Murphy, J. Paul and Mason, Richard E. and Ibrahim, Amir and et al.}, year={2023}, month={Mar} } @article{babar_harrison_blount_barnett_johnson_mergoum_mailhot_murphy_mason_ibrahim_et al._2023, title={'FLLA11019-8': A new dual-purpose facultative oat cultivar for grain and forage production in the southern United States}, ISSN={["1940-3496"]}, DOI={10.1002/plr2.20272}, abstractNote={Abstract‘FLLA11019‐8’ (Reg. no. CV‐386, PI 700040) is new facultative oat (Avena sativa L.) cultivar for the southern United States for forage, grain, cover, and wildlife food crop uses. It was co‐developed by the University of Florida and Louisiana State University Agricultural Center and was released in 2020 under the SunGrains, a cooperative small grain breeding program among seven Southern Universities. This line was derived from a single cross between two advanced breeding lines, FL0564‐Ab13 and LA06071SBSB‐S1. Exclusive marketing rights were granted to Ragan & Massey, Inc., and the line is currently commercializing under the names of RAM Forage Oats and PlotSpike Forage Oats. The University of Florida is the lead institution in this release. FLLA11019‐8 (originally named FLLA11‐19S‐8) was developed using the selected bulk breeding method and was selected as an F5:6 head row. The line was evaluated in observation, preliminary, advanced, regional, and state grain and forage yield trials from 2016 to 2021. FLLA11019‐8 was released based on the merits of its broad adaptation, excellent grain yield, volume weight, forage potential, and winter survival. It is resistant to crown rust and stem rust and moderately resistant to Barley yellow dwarf virus. It is a mid‐maturing and mid‐tall height variety. FLLA11019‐8 has semi‐prostrate plant type with vigorous early‐season growth and high tillering capacity. It has performed very well in both grain and forage trials and is broadly adapted to the southern and southeastern United States.}, journal={JOURNAL OF PLANT REGISTRATIONS}, author={Babar, Md Ali and Harrison, Stephen A. and Blount, Ann and Barnett, Ronald D. and Johnson, Jerry and Mergoum, Mohamed and Mailhot, Daniel J. and Murphy, J. Paul and Mason, Richard E. and Ibrahim, Amir and et al.}, year={2023}, month={Jan} } @article{dewitt_lyerly_guedira_holland_murphy_ward_boyles_mergoum_babar_shakiba_et al._2023, title={Bearded or smooth? Awns improve yield when wheat experiences heat stress during grain fill in the southeastern United States}, volume={74}, ISSN={["1460-2431"]}, url={https://doi.org/10.1093/jxb/erad318}, DOI={10.1093/jxb/erad318}, abstractNote={Abstract The presence or absence of awns—whether wheat heads are ‘bearded’ or ‘smooth’ – is the most visible phenotype distinguishing wheat cultivars. Previous studies suggest that awns may improve yields in heat or water-stressed environments, but the exact contribution of awns to yield differences remains unclear. Here we leverage historical phenotypic, genotypic, and climate data for wheat (Triticum aestivum) to estimate the yield effects of awns under different environmental conditions over a 12-year period in the southeastern USA. Lines were classified as awned or awnless based on sequence data, and observed heading dates were used to associate grain fill periods of each line in each environment with climatic data and grain yield. In most environments, awn suppression was associated with higher yields, but awns were associated with better performance in heat-stressed environments more common at southern locations. Wheat breeders in environments where awns are only beneficial in some years may consider selection for awned lines to reduce year-to-year yield variability, and with an eye towards future climates.}, number={21}, journal={JOURNAL OF EXPERIMENTAL BOTANY}, author={DeWitt, Noah and Lyerly, Jeanette and Guedira, Mohammed and Holland, James B. and Murphy, J. Paul and Ward, Brian P. and Boyles, Richard E. and Mergoum, Mohamed and Babar, Md Ali and Shakiba, Ehsan and et al.}, editor={Dreisigacker, SusanneEditor}, year={2023}, month={Nov}, pages={6749–6759} } @article{rebong_henriquez inoa_moore_reberg-horton_mirsky_murphy_leon_2023, title={Breeding allelopathy in cereal rye for weed suppression}, volume={11}, ISSN={["1550-2759"]}, url={https://doi.org/10.1017/wsc.2023.64}, DOI={10.1017/wsc.2023.64}, abstractNote={AbstractRapid increase in the hectarage and agricultural systems that use cover cropping for soil conservation and improvement, soil moisture retention, and weed management has highlighted the need to develop formal breeding programs for cover crop species. Cereal rye (Secale cereale L.) is preferred by many growers due to high biomass production and weed-suppression potential, which is believed to be partially due to allelopathy. Rye germplasm exhibits large variability in allelopathic activity, which could be used to breed rye with enhanced weed suppression. Here, we provide an overview of rye history and breeding and describe a strategy to develop rye lines with increased allelopathic activity. The discussion focuses on ways to deal with important challenges to achieving this goal, including obligate cross-pollination and its consequent high segregation levels and the need to quantify allelopathic activity under field conditions. This review seeks to encourage weed scientists to collaborate with plant breeders and promote the development of cover crop cultivars better suited to reduce weed populations.}, journal={WEED SCIENCE}, author={Rebong, Democrito and Henriquez Inoa, Shannon and Moore, Virginia M. and Reberg-Horton, S. Chris and Mirsky, Steven and Murphy, J. Paul and Leon, Ramon G.}, year={2023}, month={Nov} } @article{winn_acharya_merrill_lyerly_brown-guedira_cambron_harrison_reisig_murphy_2023, title={Mapping of a novel major effect Hessian fly field partial-resistance locus in southern soft red winter wheat line LA03136E71 (vol 134, pg 3911, 2021)}, volume={136}, ISSN={["1432-2242"]}, DOI={10.1007/s00122-023-04304-2}, abstractNote={At the time of publication, it appears that there was scientific literature which was contradictory to a statement made in the abstract.The contradictory statement is that "This locus was identified on a chromosome where no other Hessian fly resistance/tolerance QTL has been previously identified."}, number={4}, journal={THEORETICAL AND APPLIED GENETICS}, author={Winn, Z. J. and Acharya, R. and Merrill, K. and Lyerly, J. and Brown-Guedira, G. and Cambron, S. and Harrison, S. H. and Reisig, D. and Murphy, J. P.}, year={2023}, month={Apr} } @article{schoen_wallace_holbert_brown-guidera_harrison_murphy_sanantonio_van sanford_boyles_mergoum_et al._2023, title={Reducing the generation time in winter wheat cultivars using speed breeding}, volume={6}, ISSN={["1435-0653"]}, DOI={10.1002/csc2.20989}, abstractNote={AbstractReducing generation time is critical to achieving the goals of genetic gain in important crops like wheat (Triticum aestivum). Speed breeding (SB) has been shown to considerably reduce generation times in crop plants. Unlike spring wheat cultivars, winter wheat varieties require typically 6–9 weeks of cold treatment, called vernalization, for flowering which extends the generation time for the development of improved winter wheat cultivars. Here, we optimized the SB method using a set of 48 diverse soft red winter wheat (SRWW) cultivars by testing vernalization duration, light and temperature requirements, and the viability of seeds harvested after different durations post‐anthesis under extended daylight conditions. We have found that using a 22‐h setting (22 h day/2 h night, 25°C/22°C) in high‐density 50‐cell trays results in rapid generation advancement. We used genotypic data for a panel of soft red winter wheat varieties from the regional programs to determine the impact of photoperiod and vernalization alleles on the efficiency of the SB approach. Using a set of 48 SRWW cultivars and germplasm from Maryland and four other public breeding programs, we establish that this protocol can allow for the advancement of four generations per year in controlled conditions for winter wheat varieties, experimental lines, or emerging cultivars. Our work shows the potential to reduce generation time by ∼30 days per generation faster than what had been reported in the SB strategies for winter wheat, thus allowing for a quicker turnaround time from original cross to genetically stable experimental genotypes that can be tested in field settings.}, journal={CROP SCIENCE}, author={Schoen, Adam and Wallace, Sydney and Holbert, Meghan Fisher and Brown-Guidera, Gina and Harrison, Stephen and Murphy, Paul and Sanantonio, Nicholas and Van Sanford, David and Boyles, Richard and Mergoum, Mohamed and et al.}, year={2023}, month={Jun} } @article{winn_lyerly_brown-guedira_murphy_mason_2023, title={Utilization of a publicly available diversity panel in genomic prediction of Fusarium head blight resistance traits in wheat}, volume={5}, ISSN={["1940-3372"]}, DOI={10.1002/tpg2.20353}, abstractNote={AbstractFusarium head blight (FHB) is an economically and environmentally concerning disease of wheat (Triticum aestivum L). A two‐pronged approach of marker‐assisted selection coupled with genomic selection has been suggested when breeding for FHB resistance. A historical dataset comprised of entries in the Southern Uniform Winter Wheat Scab Nursery (SUWWSN) from 2011 to 2021 was partitioned and used in genomic prediction. Two traits were curated from 2011 to 2021 in the SUWWSN: percent Fusarium damaged kernels (FDK) and deoxynivalenol (DON) content. Heritability was estimated for each trait‐by‐environment combination. A consistent set of check lines was drawn from each year in the SUWWSN, and k‐means clustering was performed across environments to assign environments into clusters. Two clusters were identified as FDK and three for DON. Cross‐validation on SUWWSN data from 2011 to 2019 indicated no outperforming training population in comparison to the combined dataset. Forward validation for FDK on the SUWWSN 2020 and 2021 data indicated a predictive accuracy and , respectively. Forward validation for DON indicated a predictive accuracy of and , respectively. Forward validation using environments in cluster one for FDK indicated a predictive accuracy of and , respectively. Forward validation using environments in cluster one for DON indicated a predictive accuracy of and , respectively. These results indicated that selecting environments based on check performance may produce higher forward prediction accuracies. This work may be used as a model for utilizing public resources for genomic prediction of FHB resistance traits across public wheat breeding programs.}, journal={PLANT GENOME}, author={Winn, Zachary J. J. and Lyerly, Jeanette H. H. and Brown-Guedira, Gina and Murphy, Joseph P. P. and Mason, Richard Esten}, year={2023}, month={May} } @article{winn_reisig_murphy_2023, title={Yield protection afforded by imidacloprid during Hessian fly infestation in six genotypes}, volume={3}, ISSN={["1435-0645"]}, DOI={10.1002/agj2.21308}, abstractNote={AbstractThe Hessian fly (Mayetiola destructor Say) is a gall midge that infests and feeds upon wheat (Triticum aestivum L.). Recently, a new form of tolerance (QHft.nc‐7D) was identified in the breeding line LA03136E71 (PI 700336). Partial resistance allows immature Hessian fly to thrive in small numbers and does not function like antibiosis. Little is known about the potential yield drag of using partial resistance. In this study, we evaluated six genotypes: one containing QHft.nc‐7D (LA03136E71), one containing H13, and four potentially susceptible genotypes. All genotypes were evaluated with two different seed treatment regiments of imidacloprid: no treatment and a two times rate of imidacloprid. All tested genotypes were planted in six‐to‐eight replications of a full factorial design in four environments. Subsamples of yield trial plots were taken to measure percent infested tillers and a number of larvae/pupae per tiller. Plots were harvested and grain yield was recorded. There was a significant (p[>F] < 0.05) reduction of percent infested tillers and a number of larvae/pupae per tiller related to the imidacloprid treatment. Imidacloprid treatment significantly (p[>T] < 0.05) reduced the number of larvae/pupae per tiller for LA03136E71. There was no significant (p[>T] > 0.05) grain yield increase associated with treatment for LA03136E71. This indicates that a two times application of imidacloprid on LA03136E71 (QHft.nc‐7D) did not improve yield yet reduced infestation. Therefore, QHft.nc‐7D, while allowing Hessian fly to thrive on the plant, does not significantly compromise yield.}, journal={AGRONOMY JOURNAL}, author={Winn, Zachary J. J. and Reisig, Dominic and Murphy, Joseph P. P.}, year={2023}, month={Mar} } @article{dewitt_guedira_murphy_marshall_mergoum_maltecca_brown-guedira_2022, title={A network modeling approach provides insights into the environment-specific yield architecture of wheat}, volume={5}, ISSN={["1943-2631"]}, url={https://doi.org/10.1093/genetics/iyac076}, DOI={10.1093/genetics/iyac076}, abstractNote={Abstract Wheat (Triticum aestivum) yield is impacted by a diversity of developmental processes which interact with the environment during plant growth. This complex genetic architecture complicates identifying quantitative trait loci that can be used to improve yield. Trait data collected on individual processes or components of yield have simpler genetic bases and can be used to model how quantitative trait loci generate yield variation. The objectives of this experiment were to identify quantitative trait loci affecting spike yield, evaluate how their effects on spike yield proceed from effects on component phenotypes, and to understand how the genetic basis of spike yield variation changes between environments. A 358 F5:6 recombinant inbred line population developed from the cross of LA-95135 and SS-MPV-57 was evaluated in 2 replications at 5 locations over the 2018 and 2019 seasons. The parents were 2 soft red winter wheat cultivars differing in flowering, plant height, and yield component characters. Data on yield components and plant growth were used to assemble a structural equation model to characterize the relationships between quantitative trait loci, yield components, and overall spike yield. The effects of major quantitative trait loci on spike yield varied by environment, and their effects on total spike yield were proportionally smaller than their effects on component traits. This typically resulted from contrasting effects on component traits, where an increase in traits associated with kernel number was generally associated with a decrease in traits related to kernel size. In all, the complete set of identified quantitative trait loci was sufficient to explain most of the spike yield variation observed within each environment. Still, the relative importance of individual quantitative trait loci varied dramatically. Path analysis based on coefficients estimated through structural equation model demonstrated that these variations in effects resulted from both different effects of quantitative trait loci on phenotypes and environment-by-environment differences in the effects of phenotypes on one another, providing a conceptual model for yield genotype-by-environment interactions in wheat.}, number={3}, journal={GENETICS}, author={DeWitt, Noah and Guedira, Mohammed and Murphy, Joseph Paul and Marshall, David and Mergoum, Mohamed and Maltecca, Christian and Brown-Guedira, Gina}, editor={Juenger, TEditor}, year={2022}, month={May} } @article{mergoum_johnson_buck_buntin_sutton_lopez_mailhot_chen_bland_harrison_et al._2022, title={A new soft red winter wheat cultivar 'GA 08535-15LE29' adapted to Georgia and the US southeast region}, volume={5}, ISSN={["1940-3496"]}, DOI={10.1002/plr2.20235}, abstractNote={AbstractSoft red winter wheat (SRWW) (Triticum aestivum L.) production in the southeastern United States is affected by biotic and abiotic stresses that can result in yield losses and reduced acreage. Developing new cultivars with high yield, good resistance to predominant pests, and acceptable quality to maximize value in regional markets is needed. The University of Georgia (UGA) SRWW breeding program, in collaboration with institutions in the region including the Southern UNiversities GRAINS (SUNGRAINS) programs, is responding to these challenges by developing and releasing superior cultivars adapted to the region. ‘GA 08535‐15LE29’ (Reg. no. CV‐1191, PI 693269) SRWW cultivar was developed and released by the UGA College of Agricultural and Environmental Sciences and licensed to Uni South Genetics seed company in 2018 as USG 3640. GA 08535‐15LE29 is well adapted to Georgia and the U.S. southeast region with high yield and good resistance to leaf (Puccinia triticina Erikss.) and stripe (P. striiformis Westend.) rusts, Fusarium head blight (caused by Fusarium graminearum Schwabe), powdery mildew (Erisyphe graminis), and Soil‐borne wheat mosaic virus (SBWMV) diseases. GA 08535‐15LE29 showed moderate field resistance to Hessian fly [Mayetiola destructor (Say)]. GA 08535‐15LE29 has Sbm1 and Yr17/Lr37/Sr38 for resistance to SBWMV and rust diseases and has good grain volume weight and acceptable milling and baking qualities.}, journal={JOURNAL OF PLANT REGISTRATIONS}, author={Mergoum, Mohamed and Johnson, Jerry and Buck, James and Buntin, G. David and Sutton, Steve and Lopez, Benjamin and Mailhot, Daniel and Chen, Zhenbang and Bland, Dan and Harrison, Stephen and et al.}, year={2022}, month={May} } @article{ackerman_holmes_gaskins_jordan_hicks_fitzgerald_griffey_mason_harrison_murphy_et al._2022, title={Evaluation of Methods for Measuring Fusarium-Damaged Kernels of Wheat}, volume={12}, ISSN={["2073-4395"]}, url={https://www.mdpi.com/2073-4395/12/2/532}, DOI={10.3390/agronomy12020532}, abstractNote={Fusarium head blight (FHB) is one of the most economically destructive diseases of wheat (Triticum aestivum L.), causing substantial yield and quality loss worldwide. Fusarium graminearum is the predominant causal pathogen of FHB in the U.S., and produces deoxynivalenol (DON), a mycotoxin that accumulates in the grain throughout infection. FHB results in kernel damage, a visual symptom that is quantified by a human observer enumerating or estimating the percentage of Fusarium-damaged kernels (FDK) in a sample of grain. To date, FDK estimation is the most efficient and accurate method of predicting DON content without measuring presence in a laboratory. For this experiment, 1266 entries collectively representing elite varieties and SunGrains advanced breeding lines encompassing four inoculated FHB nurseries were represented in the analysis. All plots were subjected to a manual FDK count, both exact and estimated, near-infrared spectroscopy (NIR) analysis, DON laboratory analysis, and digital imaging seed phenotyping using the Vibe QM3 instrument developed by Vibe imaging analytics. Among the FDK analytical platforms used to establish percentage FDK within grain samples, Vibe QM3 showed the strongest prediction capabilities of DON content in experimental samples, R2 = 0.63, and higher yet when deployed as FDK GEBVs, R2 = 0.76. Additionally, Vibe QM3 was shown to detect a significant SNP association at locus S3B_9439629 within major FHB resistance quantitative trait locus (QTL) Fhb1. Visual estimates of FDK showed higher prediction capabilities of DON content in grain subsamples than previously expected when deployed as genomic estimated breeding values (GEBVs) (R2 = 0.71), and the highest accuracy in genomic prediction, followed by Vibe QM3 digital imaging, with average Pearson’s correlations of r = 0.594 and r = 0.588 between observed and predicted values, respectively. These results demonstrate that seed phenotyping using traditional or automated platforms to determine FDK boast various throughput and efficacy that must be weighed appropriately when determining application in breeding programs to screen for and develop resistance to FHB and DON accumulation in wheat germplasms.}, number={2}, journal={AGRONOMY-BASEL}, author={Ackerman, Arlyn J. and Holmes, Ryan and Gaskins, Ezekiel and Jordan, Kathleen E. and Hicks, Dawn S. and Fitzgerald, Joshua and Griffey, Carl A. and Mason, Richard Esten and Harrison, Stephen A. and Murphy, Joseph Paul and et al.}, year={2022}, month={Feb} } @article{winn_lyerly_ward_brown-guedira_boyles_mergoum_johnson_harrison_babar_mason_et al._2022, title={Profiling of Fusarium head blight resistance QTL haplotypes through molecular markers, genotyping-by-sequencing, and machine learning}, volume={7}, ISSN={["1432-2242"]}, DOI={10.1007/s00122-022-04178-w}, abstractNote={Marker-assisted selection is important for cultivar development. We propose a system where a training population genotyped for QTL and genome-wide markers may predict QTL haplotypes in early development germplasm. Breeders screen germplasm with molecular markers to identify and select individuals that have desirable haplotypes. The objective of this research was to investigate whether QTL haplotypes can be accurately predicted using SNPs derived by genotyping-by-sequencing (GBS). In the SunGrains program during 2020 (SG20) and 2021 (SG21), 1,536 and 2,352 lines submitted for GBS were genotyped with markers linked to the Fusarium head blight QTL: Qfhb.nc-1A, Qfhb.vt-1B, Fhb1, and Qfhb.nc-4A. In parallel, data were compiled from the 2011-2020 Southern Uniform Winter Wheat Scab Nursery (SUWWSN), which had been screened for the same QTL, sequenced via GBS, and phenotyped for: visual Fusarium severity rating (SEV), percent Fusarium damaged kernels (FDK), deoxynivalenol content (DON), plant height, and heading date. Three machine learning models were evaluated: random forest, k-nearest neighbors, and gradient boosting machine. Data were randomly partitioned into training-testing splits. The QTL haplotype and 100 most correlated GBS SNPs were used for training and tuning of each model. Trained machine learning models were used to predict QTL haplotypes in the testing partition of SG20, SG21, and the total SUWWSN. Mean disease ratings for the observed and predicted QTL haplotypes were compared in the SUWWSN. For all models trained using the SG20 and SG21, the observed Fhb1 haplotype estimated group means for SEV, FDK, DON, plant height, and heading date in the SUWWSN were not significantly different from any of the predicted Fhb1 calls. This indicated that machine learning may be utilized in breeding programs to accurately predict QTL haplotypes in earlier generations.}, journal={THEORETICAL AND APPLIED GENETICS}, author={Winn, Zachary J. and Lyerly, Jeanette and Ward, Brian and Brown-Guedira, Gina and Boyles, Richard E. and Mergoum, Mohamed and Johnson, Jerry and Harrison, Stephen and Babar, Ali and Mason, Richard E. and et al.}, year={2022}, month={Jul} } @article{ballen-taborda_lyerly_smith_howell_brown-guedira_babar_harrison_mason_mergoum_murphy_et al._2022, title={Utilizing genomics and historical data to optimize gene pools for new breeding programs: A case study in winter wheat}, volume={13}, ISSN={["1664-8021"]}, DOI={10.3389/fgene.2022.964684}, abstractNote={With the rapid generation and preservation of both genomic and phenotypic information for many genotypes within crops and across locations, emerging breeding programs have a valuable opportunity to leverage these resources to 1) establish the most appropriate genetic foundation at program inception and 2) implement robust genomic prediction platforms that can effectively select future breeding lines. Integrating genomics-enabled1 breeding into cultivar development can save costs and allow resources to be reallocated towards advanced (i.e., later) stages of field evaluation, which can facilitate an increased number of testing locations and replicates within locations. In this context, a reestablished winter wheat breeding program was used as a case study to understand best practices to leverage and tailor existing genomic and phenotypic resources to determine optimal genetics for a specific target population of environments. First, historical multi-environment phenotype data, representing 1,285 advanced breeding lines, were compiled from multi-institutional testing as part of the SunGrains cooperative and used to produce GGE biplots and PCA for yield. Locations were clustered based on highly correlated line performance among the target population of environments into 22 subsets. For each of the subsets generated, EMMs and BLUPs were calculated using linear models with the ‘lme4’ R package. Second, for each subset, TPs representative of the new SC breeding lines were determined based on genetic relatedness using the ‘STPGA’ R package. Third, for each TP, phenotypic values and SNP data were incorporated into the ‘rrBLUP’ mixed models for generation of GEBVs of YLD, TW, HD and PH. Using a five-fold cross-validation strategy, an average accuracy of r = 0.42 was obtained for yield between all TPs. The validation performed with 58 SC elite breeding lines resulted in an accuracy of r = 0.62 when the TP included complete historical data. Lastly, QTL-by-environment interaction for 18 major effect genes across three geographic regions was examined. Lines harboring major QTL in the absence of disease could potentially underperform (e.g., Fhb1 R-gene), whereas it is advantageous to express a major QTL under biotic pressure (e.g., stripe rust R-gene). This study highlights the importance of genomics-enabled breeding and multi-institutional partnerships to accelerate cultivar development.}, journal={FRONTIERS IN GENETICS}, author={Ballen-Taborda, Carolina and Lyerly, Jeanette and Smith, Jared and Howell, Kimberly and Brown-Guedira, Gina and Babar, Md. Ali and Harrison, Stephen A. A. and Mason, Richard E. E. and Mergoum, Mohamed and Murphy, J. Paul and et al.}, year={2022}, month={Oct} } @article{kloppe_boshoff_pretorius_lesch_akin_morgounov_shamanin_kuhnem_murphy_cowger_2022, title={Virulence of Blumeria graminis f. sp. tritici in Brazil, South Africa, Turkey, Russia, and Australia}, volume={13}, ISSN={["1664-462X"]}, DOI={10.3389/fpls.2022.954958}, abstractNote={The globally distributed causal agent of powdery mildew on wheat, Blumeria graminis f. sp. tritici (Bgt), is one of the most rapidly adapting plant pathogens and requires monitoring for shifts in virulence to wheat resistance (Pm) genes. Virulence frequencies were assessed in a total of 346 Bgt isolates from several countries that had either lately recorded increasing powdery mildew epidemics (Brazil, South Africa, and Australia) or not recently been surveyed (Turkey and Russia). The results were compared to previously published surveys of United States and Egyptian Bgt (390 isolates). Many of the Pm genes that have potentially been employed longer (Pm1a–Pm17) were shown to have lost effectiveness, and the complexity of virulence to those genes was higher among Brazilian isolates than those from any other country. Some cases of high virulence frequency could be linked to specific Pm gene deployments, such as the widespread planting of cultivar Wyalkatchem (Pm1a) in Australia. Virulence was also assessed to a set of Pm genes recently introgressed from diploid and tetraploid wheat relatives into a hexaploid winter wheat background and not yet commercially deployed. The isolate collections from Fertile Crescent countries (Egypt and Turkey) stood out for their generally moderate frequencies of virulence to both the older and newer Pm genes, consistent with that region’s status as the center of origin for both host and pathogen. It appeared that the recently introgressed Pm genes could be the useful sources of resistance in wheat breeding for other surveyed regions.}, journal={FRONTIERS IN PLANT SCIENCE}, author={Kloppe, Tim and Boshoff, Willem and Pretorius, Zacharias and Lesch, Driecus and Akin, Beyhan and Morgounov, Alexey and Shamanin, Vladimir and Kuhnem, Paulo and Murphy, Paul and Cowger, Christina}, year={2022}, month={Aug} } @article{mergoum_johnson_buck_sutton_lopez_bland_chen_buntin_mailhot_babar_et al._2021, title={'GA JT141-14E45': A new soft red winter wheat cultivar adapted to Georgia and the US Southeast region}, volume={8}, ISSN={["1940-3496"]}, DOI={10.1002/plr2.20070}, abstractNote={AbstractIn Georgia and the southeast region of the United States, acreage of soft red winter wheat (SRWW) (Triticum aestivum L.) has decreased in recent years. There is an urgent need to release new cultivars with high yield potential, resistance to yield‐limiting diseases and insects, and good baking quality to maximize value in regional markets. To address this, the SRWW breeding program at the University of Georgia (UGA), in collaboration with the SUNGRAINS breeding programs, developed ‘GA JT141‐14E45’ (Reg. no. CV‐1183, PI 689519), a SRWW cultivar released by the UGA College of Agricultural and Environmental Sciences and licensed to AGSouth (AGS) Genetics as AGS 3030. GA JT141‐14E45 is widely adapted to the U.S. Southeast, having high yield, good resistance to diseases such as leaf rust, stripe rust, powdery mildew, and Soil‐borne wheat mosaic virus (SBWMV) and to current biotypes of Hessian fly (Mayetiola destructor Say). It has good resistance to Fusarium head blight (FHB) or scab. GA JT141‐14E45 has good grain volume weight and acceptable milling and baking quality. GA JT141‐14E45 was derived from the cross of ‘AGS 2026’/‘Jamestown’. Jamestown was used in the cross mainly for its resistance to FHB (FHB QTL 1A‐Neuse and 1B‐Jamestown). AGS 2026 is a UGA cultivar released in 2007 with very good disease resistance to rusts (Yr17/Lr37/Sr38), Hessian fly resistance (H13), and excellent yield.}, journal={JOURNAL OF PLANT REGISTRATIONS}, author={Mergoum, Mohamed and Johnson, Jerry W. and Buck, James W. and Sutton, Steve and Lopez, Benjamin and Bland, Daniel and Chen, Z. and Buntin, G. D. and Mailhot, Daniel J. and Babar, Md A. and et al.}, year={2021}, month={Aug} } @article{mergoum_johnson_buck_sutton_lopez_bland_chen_buntin_mailhot_babar_et al._2021, title={A new soft red winter wheat cultivar, 'GA 07353-14E19', adapted to Georgia and the US Southeast environments}, volume={15}, ISSN={["1940-3496"]}, DOI={10.1002/plr2.20113}, abstractNote={AbstractSoft red winter wheat (SRWW) (Triticum aestivum L.), historically a major crop in Georgia and the U.S. Southeast (SE) region, has been challenged by numerous biotic and abiotic constraints resulting in decreased hectarage in recent years. Hence, an urgent need exists to release new cultivars with high yield potential, good resistance to predominant diseases and insects, and acceptable quality attributes to capture and maximize value in regional markets. The SRWW breeding program at the University of Georgia (UGA), in collaboration with the Southeastern University GRAINS (SUNGRAINS) breeding programs, is responding to these challenges by developing and releasing superior SRWW cultivars adapted to Georgia and the SE wheat region. ‘GA 07353‐14E19’ (Reg. no. CV‐1179, PI 689520), a SRWW cultivar developed by the UGA small grains breeding program, was released by the UGA College of Agricultural and Environmental Sciences and licensed to Stratton Seed Company in 2017 as GO WHEAT 2032. GA 07353‐14E19 is adapted to the SE region with high yield, good resistance to prevalent diseases, including leaf and stripe rusts, Fusarium head blight, powdery mildew, and Soil‐borne wheat mosaic virus. GA 07353‐14E19 also showed good resistance to current biotypes of Hessian fly. GA 07353‐14E19 possesses the H13, Sbm1, and Yr17–Lr37–Sr38 genes that protect it against the above pests. It has very good grain volume weight and good milling and baking quality as a SRWW.}, number={2}, journal={JOURNAL OF PLANT REGISTRATIONS}, author={Mergoum, Mohamed and Johnson, Jerry W. and Buck, James W. and Sutton, Steve and Lopez, Benjamin and Bland, Daniel and Chen, Z. and Buntin, G. D. and Mailhot, Daniel J. and Babar, Md A. and et al.}, year={2021}, month={May}, pages={337–344} } @article{dewitt_guedira_lauer_murphy_marshall_mergoum_johnson_holland_brown-guedira_2021, title={Characterizing the oligogenic architecture of plant growth phenotypes informs genomic selection approaches in a common wheat population}, volume={22}, ISSN={["1471-2164"]}, DOI={10.1186/s12864-021-07574-6}, abstractNote={Abstract Background Genetic variation in growth over the course of the season is a major source of grain yield variation in wheat, and for this reason variants controlling heading date and plant height are among the best-characterized in wheat genetics. While the major variants for these traits have been cloned, the importance of these variants in contributing to genetic variation for plant growth over time is not fully understood. Here we develop a biparental population segregating for major variants for both plant height and flowering time to characterize the genetic architecture of the traits and identify additional novel QTL. Results We find that additive genetic variation for both traits is almost entirely associated with major and moderate-effect QTL, including four novel heading date QTL and four novel plant height QTL. FT2 and Vrn-A3 are proposed as candidate genes underlying QTL on chromosomes 3A and 7A, while Rht8 is mapped to chromosome 2D. These mapped QTL also underlie genetic variation in a longitudinal analysis of plant growth over time. The oligogenic architecture of these traits is further demonstrated by the superior trait prediction accuracy of QTL-based prediction models compared to polygenic genomic selection models. Conclusions In a population constructed from two modern wheat cultivars adapted to the southeast U.S., almost all additive genetic variation in plant growth traits is associated with known major variants or novel moderate-effect QTL. Major transgressive segregation was observed in this population despite the similar plant height and heading date characters of the parental lines. This segregation is being driven primarily by a small number of mapped QTL, instead of by many small-effect, undetected QTL. As most breeding populations in the southeast U.S. segregate for known QTL for these traits, genetic variation in plant height and heading date in these populations likely emerges from similar combinations of major and moderate effect QTL. We can make more accurate and cost-effective prediction models by targeted genotyping of key SNPs. }, number={1}, journal={BMC GENOMICS}, author={DeWitt, Noah and Guedira, Mohammed and Lauer, Edwin and Murphy, J. Paul and Marshall, David and Mergoum, Mohamed and Johnson, Jerry and Holland, James B. and Brown-Guedira, Gina}, year={2021}, month={May} } @article{winn_acharya_merrill_lyerly_brown-guedira_cambron_harrison_reisig_murphy_2021, title={Mapping of a novel major effect Hessian fly field partial-resistance locus in southern soft red winter wheat line LA03136E71}, volume={8}, ISSN={["1432-2242"]}, DOI={10.1007/s00122-021-03936-6}, abstractNote={Hessian fly resistance has centralized around resistance loci that are biotype specific. We show that field resistance is evident and controlled by a single locus on chromosome 7D. Hessian flies (Mayetiola destructor Say) infest and feed upon wheat (Triticum aestivum L) resulting in significant yield loss. Genetically resistant cultivars are the most effective method of Hessian fly management. Wheat breeders in the southern USA have observed cultivars exhibiting a "field resistance" to Hessian fly that is not detectable by greenhouse assay. The resistant breeding line "LA03136E71" and susceptible cultivar "Shirley" were crossed to develop a population of 200 random F 4:5 lines using single seed descent. The population was evaluated in a total of five locations in North Carolina during the 2019, 2020, and 2021 seasons. A subsample of each plot was evaluated for the total number of tillers, number of infested tillers, and total number of larvae/pupae. From these data, the percent infested tillers, number of larvae/pupae per tiller, and the number of larvae/pupae per infested tiller were estimated. In all within and across environment combinations for all traits recorded, the genotype effect was significant (p < 0.05). Interval mapping identified a single large effect QTL distally on the short arm of chromosome 7D for all environment-trait combinations. This locus was identified on a chromosome where no other Hessian fly resistance/tolerance QTL has been previously identified. This novel Hessian fly partial-resistance QTL is termed QHft.nc-7D. Fine mapping must be conducted in this region to narrow down the causal agents responsible for this trait, and investigation into the mode of action is highly suggested.}, journal={THEORETICAL AND APPLIED GENETICS}, author={Winn, Z. J. and Acharya, R. and Merrill, K. and Lyerly, J. and Brown-Guedira, G. and Cambron, S. and Harrison, S. H. and Reisig, D. and Murphy, J. P.}, year={2021}, month={Aug} } @article{ibrahim_sutton_johnson_mergoum_simoneaux_harrison_murphy_mason_babar_neely_et al._2021, title={Registration of 'GA06343-13E2 (TX-EL2)' soft red winter wheat}, volume={15}, ISBN={1940-3496}, DOI={10.1002/plr2.20031}, abstractNote={Abstract‘GA06343‐13E2 (TX‐EL2)’ (Reg. no. CV‐1172, PI 695071), a medium‐height, medium‐maturing soft red winter wheat (Triticum aestivum L.) (SRWW), was jointly released by Texas A&M AgriLife Research and the University of Georgia Agricultural Experiment Station in 2019. GA06343‐13E2 (TX‐EL2) was released based on merits of its wide area of adaptation and above‐average grain yield in Texas in particular and the Gulf Atlantic SRWW growing areas in general, in addition to average grain volume weight, good leaf rust and stripe rust resistance, and good end‐use quality characteristics. GA06343‐13E2 (TX‐EL2) was derived from the cross GA011638‐G1/GA961592‐8//GA991336‐47 made at the University of Georgia. The pedigree of GA011638‐G1 is GA01034 (‘AGS 2000’*3/96667)/AGS 2000. The pedigrees of GA961592‐8 and GA991336‐47 are GA951329 (GA88129‐32‐3‐5/GA87467‐14‐1‐14‐1)/GA88127‐1‐3‐3 and GA92432‐21‐5‐2/GA981622 [AGS 2000/Pioneer ‘26R61’ (XW663)], respectively. Authorized seed classes of GA06343‐13E2 (TX‐EL2) in the United States will be breeder, foundation, registered, and certified. We will submit GA06343‐13E2 (TX‐EL2) for U.S. Plant Variety Protection with the certification option.}, number={1}, journal={JOURNAL OF PLANT REGISTRATIONS}, author={Ibrahim, Amir M. H. and Sutton, Russell and Johnson, Jerry W. and Mergoum, Mohamed and Simoneaux, Bryan and Harrison, Stephen A. and Murphy, J. Paul and Mason, R. Esten and Babar, Md A. and Neely, Clark and et al.}, year={2021}, month={Jan}, pages={107–112} } @article{mergoum_johnson_buck_sutton_lopez_bland_chen_buntin_mailhot_babar_et al._2021, title={Soft red winter wheat 'GA 051207-14E53': Adapted cultivar to Georgia and the US Southeast region}, volume={15}, ISSN={["1940-3496"]}, DOI={10.1002/plr2.20102}, abstractNote={AbstractSoft red winter wheat (SRWW) (Triticum aestivum L.) is a major crop in Georgia and the U.S. Southeast (SE) region. Hence, new cultivars with high yield potential, high resistance levels to predominant pests, and adequate quality parameters are required to capture and maximize regional market values. Therefore, the University of Georgia SRWW breeding program in collaboration with the SUNGRAINS breeding programs, aims to develop and release SRWW cultivars adapted to Georgia and the SE wheat region with high yield, quality, and pest resistance. ‘GA 051207‐14E53’ SRWW (Reg. no. CV‐1168, PI 689518) was developed and released by the University of Georgia and licensed to AGSouth Genetics Company in 2017 under the name AGS 3040. GA 051207‐14E53 is well adapted to Georgia and the SE region. It has high yield and high resistance to leaf rust, stripe rust, and Soil‐borne wheat mosaic virus. It has medium resistance to powdery mildew and to biotypes C and O of Hessian fly and is resistant to biotypes B and L. GA 051207‐14E53 has good Fusarium head blight resistance. GA 051207‐14E53 possesses H9, Sbm1, and the 2NS:2AS alien introgression from Aegilops ventricosa Tausch, having the Yr17/Lr37/Sr38 genes that protect it against these pests. Grain volume weight and milling and baking qualities of GA 051207‐14E53 are good and meet the SRWW grade standards.}, number={1}, journal={JOURNAL OF PLANT REGISTRATIONS}, author={Mergoum, Mohamed and Johnson, Jerry W. and Buck, James W. and Sutton, Steve and Lopez, Benjamin and Bland, Daniel and Chen, Z. and Buntin, G. D. and Mailhot, Daniel J. and Babar, Md A. and et al.}, year={2021}, month={Jan}, pages={132–139} } @article{vann_reberg-horton_castillo_murphy_martins_mirsky_saha_mcgee_2021, title={Differences among eighteen winter pea genotypes for forage and cover crop use in the southeastern United States}, volume={61}, ISSN={["1435-0653"]}, DOI={10.1002/csc2.20355}, abstractNote={AbstractWinter pea (Pisum sativum L.) can be used as a forage and cover crop in the southeast and mid‐Atlantic United states; however, minimal effort has been devoted to optimize winter pea genetics for forage and cover crop production in these regions. Studies were conducted from 2015–2017 in Maryland and North Carolina screening 18 winter pea genotypes for forage and cover crop use. Winter pea genotypes were compared with widely grown crimson clover (Trifolium incarnatum L.) and hairy vetch (Vicia villosa Roth]. All legume genotypes were harvested across four timings. Legume winter hardiness, disease incidence, biomass production, quality, and N release were estimated. Winter hardiness was severe with many winter pea genotypes at the Maryland environments, which restricted winter pea biomass production. There was considerable variation for disease incidence among the winter pea genotypes depending on biotic stressors at each environment. At the North Carolina environments, several winter pea genotypes produced similar biomass to crimson clover and hairy vetch across harvest timings. At the Maryland environments, crimson clover and hairy vetch biomass exceeded winter pea biomass. The winter pea genotypes varied considerably for quality traits including protein, lignin, and cellulose. Relative forage value declined as biomass harvest was delayed and was generally higher with all winter pea genotypes than crimson clover or hairy vetch. These results show wide genetic variation in the winter pea genotypes screened for biomass and quality; this variation could be utilized in breeding efforts to enhance winter pea production in the region.}, number={2}, journal={CROP SCIENCE}, author={Vann, Rachel A. and Reberg-Horton, S. Chris and Castillo, Miguel S. and Murphy, J. Paul and Martins, Lais B. and Mirsky, Steven B. and Saha, Uttam and McGee, Rebecca J.}, year={2021}, month={Mar}, pages={947–965} } @article{carpenter_wright_malla_singh_van sanford_clark_harrison_murphy_costa_chao_et al._2020, title={Identification and validation of Fusarium head blight resistance QTL in the US soft red winter wheat cultivar 'Jamestown'}, volume={60}, ISSN={["1435-0653"]}, DOI={10.1002/csc2.20307}, abstractNote={AbstractUse of genetic resistance is one of the most important strategies to manage the devastating disease Fusarium head blight (FHB) in wheat. Numerous quantitative trait loci (QTL) having varying effects on reducing FHB and the mycotoxin deoxynivalenol (DON) accumulation have been reported from Asian, European, or distant sources such as wild relatives of wheat (Triticum aestivum L.). However, coming from nonadapted backgrounds, the incorporation of such QTL into regional breeding programs has often resulted in the simultaneous transfer of other undesirable traits. Therefore, it is important to identify, characterize, and deploy sources of genetic resistance that do not suffer from poor adaptability and/or linkage drag. In the present work, QTL associated with FHB resistance in a high‐yielding, moderately resistant soft red winter wheat cultivar ‘Jamestown’ were mapped and validated. The QTL mapping was done using a recombinant inbred line (RIL) population of Pioneer ‘25R47’ × Jamestown having 186 individuals. Phenotyping over 2 yr at three locations, and genotyping using the 90K single nucleotide polymorphism (SNP) platform identified two new QTL, named QFHB.vt‐1B.1 and QFHB.vt‐1B.2, on the chromosome 1B long arm. The QTL contributed to FHB incidence, FHB severity, Fusarium‐damaged kernels, and DON content. Independent mapping of these QTL using two additional RIL populations of FG95195 × Jamestown (170 RILs) and Jamestown × LA97113UC‐124 (77 RILs) validated their stability and effectiveness in different genetic backgrounds. Kompetitive allele specific polymerase chain reaction (KASP) assays were developed using linked SNPs for marker‐assisted selection of the QTL. These QTL are being used in breeding programs to develop FHB‐resistant, high‐yielding varieties.}, number={6}, journal={CROP SCIENCE}, author={Carpenter, Neal R. and Wright, Emily and Malla, Subas and Singh, Lovepreet and Van Sanford, David and Clark, Anthony and Harrison, Stephen and Murphy, J. Paul and Costa, Jose and Chao, Shiaoman and et al.}, year={2020}, pages={2919–2930} } @article{guo_pradhan_shahi_khan_mcbreen_bai_murphy_babar_2020, title={Increased Prediction Accuracy Using Combined Genomic Information and Physiological Traits in A Soft Wheat Panel Evaluated in Multi-Environments}, volume={10}, ISSN={["2045-2322"]}, DOI={10.1038/s41598-020-63919-3}, abstractNote={AbstractAn integration of field-based phenotypic and genomic data can potentially increase the genetic gain in wheat breeding for complex traits such as grain and biomass yield. To validate this hypothesis in empirical field experiments, we compared the prediction accuracy between multi-kernel physiological and genomic best linear unbiased prediction (BLUP) model to a single-kernel physiological or genomic BLUP model for grain yield (GY) using a soft wheat population that was evaluated in four environments. The physiological data including canopy temperature (CT), SPAD chlorophyll content (SPAD), membrane thermostability (MT), rate of senescence (RS), stay green trait (SGT), and NDVI values were collected at four environments (2016, 2017, and 2018 at Citra, FL; 2017 at Quincy, FL). Using a genotyping-by-sequencing (GBS) approach, a total of 19,353 SNPs were generated and used to estimate prediction model accuracy. Prediction accuracies of grain yield evaluated in four environments improved when physiological traits and/or interaction effects (genotype × environment or physiology × environment) were included in the model compared to models with only genomic data. The proposed multi-kernel models that combined physiological and genomic data showed 35 to 169% increase in prediction accuracy compared to models with only genomic data included when heading date was used as a covariate. In general, higher response to selection was captured by the model combing effects of physiological and genotype × environment interaction compared to other models. The results of this study support the integration of field-based physiological data into GY prediction to improve genetic gain from selection in soft wheat under a multi-environment context.}, number={1}, journal={SCIENTIFIC REPORTS}, author={Guo, Jia and Pradhan, Sumit and Shahi, Dipendra and Khan, Jahangir and Mcbreen, Jordan and Bai, Guihua and Murphy, J. Paul and Babar, Md Ali}, year={2020}, month={Apr} } @article{guo_khan_pradhan_shahi_khan_avci_mcbreen_harrison_brown-guedira_murphy_et al._2020, title={Multi-Trait Genomic Prediction of Yield-Related Traits in US Soft Wheat under Variable Water Regimes}, volume={11}, ISSN={["2073-4425"]}, DOI={10.3390/genes11111270}, abstractNote={The performance of genomic prediction (GP) on genetically correlated traits can be improved through an interdependence multi-trait model under a multi-environment context. In this study, a panel of 237 soft facultative wheat (Triticum aestivum L.) lines was evaluated to compare single- and multi-trait models for predicting grain yield (GY), harvest index (HI), spike fertility (SF), and thousand grain weight (TGW). The panel was phenotyped in two locations and two years in Florida under drought and moderately drought stress conditions, while the genotyping was performed using 27,957 genotyping-by-sequencing (GBS) single nucleotide polymorphism (SNP) makers. Five predictive models including Multi-environment Genomic Best Linear Unbiased Predictor (MGBLUP), Bayesian Multi-trait Multi-environment (BMTME), Bayesian Multi-output Regressor Stacking (BMORS), Single-trait Multi-environment Deep Learning (SMDL), and Multi-trait Multi-environment Deep Learning (MMDL) were compared. Across environments, the multi-trait statistical model (BMTME) was superior to the multi-trait DL model for prediction accuracy in most scenarios, but the DL models were comparable to the statistical models for response to selection. The multi-trait model also showed 5 to 22% more genetic gain compared to the single-trait model across environment reflected by the response to selection. Overall, these results suggest that multi-trait genomic prediction can be an efficient strategy for economically important yield component related traits in soft wheat.}, number={11}, journal={GENES}, author={Guo, Jia and Khan, Jahangir and Pradhan, Sumit and Shahi, Dipendra and Khan, Naeem and Avci, Muhsin and Mcbreen, Jordan and Harrison, Stephen and Brown-Guedira, Gina and Murphy, Joseph Paul and et al.}, year={2020}, month={Nov} } @article{meier_malla_oakes_murphy_baik_chao_griffey_2020, title={Registration of three soft red winter wheat germplasm lines with exceptional milling and cookie baking performance}, volume={14}, ISSN={["1940-3496"]}, DOI={10.1002/plr2.20055}, abstractNote={AbstractThe release of soft red winter wheat (Triticum aestivum, L.) germplasm lines VA11DH‐P46xTrib‐28 (Reg. no. GP‐1048, PI 691656), VA11DH‐P46xTrib‐99 (Reg. no. GP‐1049, PI 691657), and VA11DH‐P46xTrib‐103 (Reg. no. GP‐1050, PI 691658) is intended to provide breeders with genetic material having exceptional milling and baking quality performance. The quantitative nature of milling and baking performance makes improvement and early generation selection difficult. Marker assisted and genomic selection breeding schemes can be improved by introducing breeding material with superior end‐use quality and use of known predictive DNA markers. These three lines have acceptable agronomic performance with grain yields (4605–5733 kg ha−1) similar to or higher than those of Pioneer ‘26R46’ (4568 kg ha−1). The lines have exceptional milling and baking performance with mean flour yields (733–736 g kg−1), softness equivalence (550–573 g kg−1), flour protein (89–94 g kg−1), solvent retention capacity for lactic acid (1162–1189 g kg−1) and sodium carbonate (672–697 g kg−1), and cookie diameters (19.1–19.5 cm) that are better than or similar to (p < .05) those of Pioneer 26R46 (721 g kg−1, 531 g kg−1, 93 g kg−1, 1221 g kg−1, 703 g kg−1, and 18.9 cm).}, number={3}, journal={JOURNAL OF PLANT REGISTRATIONS}, author={Meier, Nicholas A. and Malla, Subas and Oakes, Joseph C. and Murphy, J. Paul and Baik, Byung-Kee and Chao, Shiaoman and Griffey, Carl A.}, year={2020}, month={Sep}, pages={450–456} } @article{hayat_mason_lozada_acuna_holder_larkin_winn_murray_murphy_moon_et al._2019, title={Effects of allelic variation at Rht-B1 and Rht-D1 on grain yield and agronomic traits of southern US soft red winter wheat}, volume={215}, ISSN={["1573-5060"]}, DOI={10.1007/s10681-019-2478-2}, number={10}, journal={EUPHYTICA}, author={Hayat, Habibullah and Mason, R. Esten and Lozada, Dennis N. and Acuna, Andrea and Holder, Amanda and Larkin, Dylan and Winn, Zachary and Murray, Jamison and Murphy, J. Paul and Moon, David E. and et al.}, year={2019}, month={Oct} } @article{dewitt_guedira_lauer_sarinelli_tyagi_fu_hao_murphy_marshall_akhunova_et al._2020, title={Sequence-based mapping identifies a candidate transcription repressor underlying awn suppression at the B1 locus in wheat}, volume={225}, ISSN={["1469-8137"]}, DOI={10.1111/nph.16152}, abstractNote={Summary Awns are stiff, hair‐like structures which grow from the lemmas of wheat (Triticum aestivum) and other grasses that contribute to photosynthesis and play a role in seed dispersal. Variation in awn length in domesticated wheat is controlled primarily by three major genes, most commonly the dominant awn suppressor Tipped1 (B1). This study identifies a transcription repressor responsible for awn inhibition at the B1 locus. Association mapping was combined with analysis in biparental populations to delimit B1 to a distal region of 5AL colocalized with QTL for number of spikelets per spike, kernel weight, kernel length, and test weight. Fine‐mapping located B1 to a region containing only two predicted genes, including C2H2 zinc finger transcriptional repressor TraesCS5A02G542800 upregulated in developing spikes of awnless individuals. Deletions encompassing this candidate gene were present in awned mutants of an awnless wheat. Sequence polymorphisms in the B1 coding region were not observed in diverse wheat germplasm whereas a nearby polymorphism was highly predictive of awn suppression. Transcriptional repression by B1 is the major determinant of awn suppression in global wheat germplasm. It is associated with increased number of spikelets per spike and decreased kernel size. }, number={1}, journal={NEW PHYTOLOGIST}, author={DeWitt, Noah and Guedira, Mohammed and Lauer, Edwin and Sarinelli, Martin and Tyagi, Priyanka and Fu, Daolin and Hao, QunQun and Murphy, J. Paul and Marshall, David and Akhunova, Alina and et al.}, year={2020}, month={Jan}, pages={326–339} } @article{sarinelli_murphy_tyagi_holland_johnson_mergoum_mason_babar_harrison_sutton_et al._2019, title={Training population selection and use of fixed effects to optimize genomic predictions in a historical USA winter wheat panel}, volume={132}, ISSN={["1432-2242"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85060724945&partnerID=MN8TOARS}, DOI={10.1007/s00122-019-03276-6}, abstractNote={The optimization of training populations and the use of diagnostic markers as fixed effects increase the predictive ability of genomic prediction models in a cooperative wheat breeding panel. Plant breeding programs often have access to a large amount of historical data that is highly unbalanced, particularly across years. This study examined approaches to utilize these data sets as training populations to integrate genomic selection into existing pipelines. We used cross-validation to evaluate predictive ability in an unbalanced data set of 467 winter wheat (Triticum aestivum L.) genotypes evaluated in the Gulf Atlantic Wheat Nursery from 2008 to 2016. We evaluated the impact of different training population sizes and training population selection methods (Random, Clustering, PEVmean and PEVmean1) on predictive ability. We also evaluated inclusion of markers associated with major genes as fixed effects in prediction models for heading date, plant height, and resistance to powdery mildew (caused by Blumeria graminis f. sp. tritici). Increases in predictive ability as the size of the training population increased were more evident for Random and Clustering training population selection methods than for PEVmean and PEVmean1. The selection methods based on minimization of the prediction error variance (PEV) outperformed the Random and Clustering methods across all the population sizes. Major genes added as fixed effects always improved model predictive ability, with the greatest gains coming from combinations of multiple genes. Maximum predictabilities among all prediction methods were 0.64 for grain yield, 0.56 for test weight, 0.71 for heading date, 0.73 for plant height, and 0.60 for powdery mildew resistance. Our results demonstrate the utility of combining unbalanced phenotypic records with genome-wide SNP marker data for predicting the performance of untested genotypes.}, number={4}, journal={THEORETICAL AND APPLIED GENETICS}, author={Sarinelli, J. Martin and Murphy, J. Paul and Tyagi, Priyanka and Holland, James B. and Johnson, Jerry W. and Mergoum, Mohamed and Mason, Richard E. and Babar, Ali and Harrison, Stephen and Sutton, Russell and et al.}, year={2019}, month={Apr}, pages={1247–1261} } @article{cowger_mehra_arellano_meyers_murphy_2018, title={Virulence Differences in Blumeria graminis f. sp tritici from the Central and Eastern United States}, volume={108}, ISSN={["1943-7684"]}, DOI={10.1094/phyto-06-17-0211-r}, abstractNote={ Wheat powdery mildew is a disease of global importance that occurs across a wide geographic area in the United States. A virulence survey of Blumeria graminis f. sp. tritici, the causal agent, was conducted by sampling 36 wheat fields in 15 U.S. states in the years 2013 and 2014. Using a hierarchical sampling protocol, isolates were derived from three separated plants at each of five separated sites within each field in order to assess the spatial distribution of pathotypes. In total, 1,017 isolates from those fields were tested individually on single-gene differential cultivars containing a total of 21 powdery mildew resistance (Pm) genes. Several recently introgressed mildew resistance genes from wild wheat relatives (Pm37, Pm53, MlAG12, NCAG13, and MlUM15) exhibited complete or nearly complete resistance to all local B. graminis f. sp. tritici populations from across the sampled area. One older gene, Pm4b, also retained at least some efficacy across the sampled area. The B. graminis f. sp. tritici population sampled from Arkansas and Missouri, on the western edge of the eastern soft red winter wheat region, had virulence profiles more similar to other soft wheat mildew populations than to the geographically closer population from hard wheat fields in the Plains states of Oklahoma, Nebraska, and Kansas. The Plains population differed in that it was avirulent to several Pm genes long defeated in the soft-wheat-growing areas. Virulence complexity was greatest east of the Mississippi River, and diminished toward the west. Several recently introgressed Pm genes (Pm25, Pm34, Pm35, and NCA6) that are highly effective against mildew in the field in North Carolina were unexpectedly susceptible to eastern-U.S. B. graminis f. sp. tritici populations in detached-leaf tests. Sampled fields displayed a wide range of pathotype diversity and spatial distribution, suggesting that epidemics are caused by varying numbers of pathotypes in all regions. The research confirmed that most long-used Pm genes are defeated in the eastern United States, and the U.S. B. graminis f. sp. tritici population has different virulence profiles in the hard- and soft-wheat regions, which are likely maintained by host selection, isolation by distance, and west-to-east gene flow. }, number={3}, journal={PHYTOPATHOLOGY}, author={Cowger, Christina and Mehra, Lucky and Arellano, Consuelo and Meyers, Emily and Murphy, J. Paul}, year={2018}, month={Mar}, pages={402–411} } @article{johnson_chen_buck_buntin_babar_mason_harrison_murphy_ibrahim_sutton_et al._2017, title={'GA 03564-12E6': A High-Yielding Soft Red Winter Wheat Cultivar Adapted to Georgia and the Southeastern Regions of the United States}, volume={11}, ISSN={["1940-3496"]}, DOI={10.3198/jpr2016.07.0036crc}, abstractNote={Soft red winter wheat (SRWW) (Triticum aestivum L.) is a major crop in the southeastern region of the United States and in Georgia. Although wheat acreages have been decreasing in Georgia and the SE region in recent years, more than 100,000 ha were grown to SRWW in 2015. Newly released cultivars must have high yield potential, excellent resistance levels to predominant diseases and insects, and good quality to capture and maximize regional market value. One objective of the SRWW breeding program at the University of Georgia (UGA) is to develop and release SRWW cultivars adapted to the SE wheat region with high yield, quality, and pest resistance. ‘GA 03564‐12E6’ (Reg. No. CV‐1122, PI 677366) SRWW was developed by the UGA small grains breeding program and the SUNGRAINS cooperative and released by the UGA College of Agricultural and Environmental Sciences and licensed to Limagrain Cereal Seeds as L11544 in 2015. GA 03564‐12E6 was released primarily for its wide adaptation to the SE region with high grain yield, excellent Hessian fly resistance, and excellent grain volume weight. Additionally, GA 03564‐12E6 has good resistance to races of leaf rust and stripe rust predominant in Georgia and the SE United States. It has good resistance to powdery mildew (caused by Blumeria graminis f. sp. tritici) and Soil‐borne wheat mosaic virus and has acceptable SRWW milling and baking quality. However, it is susceptible to Fusarium head blight (FHB) or scab [caused by Fusarium graminearum Schwabe; teleomorph Gibberella zeae (Schwein.) Petch].}, number={2}, journal={JOURNAL OF PLANT REGISTRATIONS}, author={Johnson, Jerry W. and Chen, Z. and Buck, James W. and Buntin, G. D. and Babar, Md A. and Mason, Richard E. and Harrison, Stephen A. and Murphy, J. Paul and Ibrahim, Amir M. H. and Sutton, Russell L. and et al.}, year={2017}, month={May}, pages={159–164} } @article{harrison_babar_barnett_blount_johnson_mergoum_mason_murphy_simoneaux_ibrahim_2017, title={'LA05006', a Dual-Purpose Oat for Louisiana and Other Southeastern Regions of the USA}, volume={11}, ISSN={["1940-3496"]}, DOI={10.3198/jpr2016.08.0040crc}, abstractNote={‘LA05006’ (Reg. No. CV‐382, PI 678581), a winter‐type, dual‐purpose oat (Avena sativa L.) suited for grain and forage production, was codeveloped by Louisiana State University Agricultural Center and the University of Florida and was released in 2012 under the SunGrains cooperative small grain breeding program among six southeastern universities. Exclusive marketing rights were licensed to Plantation Seed Conditioner, Newton, GA, for sales under the name ‘Horizon 306’. This line was derived from a single cross, ‘Plot Spike LA9339’/’TAMO 405’, and was’ tested as LA05006GSBS‐65‐S1. LA05006 was developed using a selected bulk breeding method and was selected as an F5:6 head row. It was evaluated in preliminary, advanced, regional, and state grain and forage yield trials from 2010 to 2012. It is a midmaturing, medium to midtall oat with excellent forage yield and very good grain yield and test weight and also demonstrates excellent lodging resistance. LA05006 was observed to be uniform and stable from 2010 to present. It possesses a semiprostrate winter growth habit and has large leaves that are dark green in color. LA05006 is resistant to stem rust and has shown good resistance to crown rust. Average winter and spring forage yield of LA05006 was slightly higher than other popular dual‐purpose winter oat cultivars (‘Horizon 201’, ‘Horizon 270’, and Plot Spike LA9339) and was similar to ‘LA99016’. LA05006 has broad environmental adaptation and has performed well in Louisiana, Florida, Georgia, Texas, and Mississippi.}, number={2}, journal={JOURNAL OF PLANT REGISTRATIONS}, author={Harrison, S. A. and Babar, M. A. and Barnett, R. D. and Blount, A. R. and Johnson, J. W. and Mergoum, M. and Mason, E. and Murphy, J. P. and Simoneaux, B. and Ibrahim, A. M. H.}, year={2017}, month={May}, pages={89–94} } @article{klos_yimer_babiker_beattie_bonman_carson_chong_harrison_ibrahim_kolb_et al._2017, title={Genome-Wide Association Mapping of Crown Rust Resistance in Oat Elite Germplasm}, volume={10}, ISSN={["1940-3372"]}, DOI={10.3835/plantgenome2016.10.0107}, abstractNote={Oat crown rust, caused by Puccinia coronata f. sp. avenae, is a major constraint to oat (Avena sativa L.) production in many parts of the world. In this first comprehensive multienvironment genome‐wide association map of oat crown rust, we used 2972 single‐nucleotide polymorphisms (SNPs) genotyped on 631 oat lines for association mapping of quantitative trait loci (QTL). Seedling reaction to crown rust in these lines was assessed as infection type (IT) with each of 10 crown rust isolates. Adult plant reaction was assessed in the field in a total of 10 location–years as percentage severity (SV) and as infection reaction (IR) in a 0‐to‐1 scale. Overall, 29 SNPs on 12 linkage groups were predictive of crown rust reaction in at least one experiment at a genome‐wide level of statistical significance. The QTL identified here include those in regions previously shown to be linked with seedling resistance genes Pc48, Pc58a, Pc68, Pc71, Pc91, and PcKM and also with adult‐plant resistance and adaptation‐related QTL. In addition, QTL on linkage groups Mrg03, Mrg08, and Mrg23 were identified in regions not previously associated with crown rust resistance. Evaluation of marker genotypes in a set of crown rust differential lines supported Pc91 as the identity of QPc.CORE.18.3. The SNPs with rare alleles associated with lower disease scores may be suitable for use in marker‐assisted selection of oat lines for crown rust resistance.}, number={2}, journal={PLANT GENOME}, author={Klos, Kathy Esvelt and Yimer, Belayneh A. and Babiker, Ebrahiem M. and Beattie, Aaron D. and Bonman, J. Michael and Carson, Martin L. and Chong, James and Harrison, Stephen A. and Ibrahim, Amir M. H. and Kolb, Frederic L. and et al.}, year={2017}, month={Jul} } @article{livingston_tuong_murphy_gusta_willick_wisniewski_2018, title={High-definition infrared thermography of ice nucleation and propagation in wheat under natural frost conditions and controlled freezing}, volume={247}, ISSN={0032-0935 1432-2048}, url={http://dx.doi.org/10.1007/S00425-017-2823-4}, DOI={10.1007/S00425-017-2823-4}, abstractNote={An extremely high resolution infrared camera demonstrated various freezing events in wheat under natural conditions. Many of those events shed light on years of misunderstanding regarding freezing in small grains. Infrared thermography has enhanced our knowledge of ice nucleation and propagation in plants through visualization of the freezing process. The majority of infrared analyses have been conducted under controlled conditions and often on individual organs instead of whole plants. In the present study, high-definition (1280 × 720 pixel resolution) infrared thermography was used under natural conditions to visualize the freezing process of wheat plants during freezing events in 2016 and 2017. Plants within plots were found to freeze one at a time throughout the night and in an apparently random manner. Leaves on each plant also froze one at a time in an age-dependent pattern with oldest leaves freezing first. Contrary to a common assumption that freezing begins in the upper parts of leaves; freezing began at the base of the plant and spread upwards. The high resolution camera used was able to verify that a two stage sequence of freezing began within vascular bundles. Neither of the two stages was lethal to leaves, but a third stage was demonstrated at colder temperatures that was lethal and was likely a result of dehydration stress; this stage of freezing was not detectable by infrared. These results underscore the complexity of the freezing process in small grains and indicate that comprehensive observational studies are essential to identifying and selecting freezing tolerance traits in grain crops.}, number={4}, journal={Planta}, publisher={Springer Science and Business Media LLC}, author={Livingston, David P. and Tuong, Tan D. and Murphy, J. Paul and Gusta, Lawrence V. and Willick, Ian and Wisniewski, Micheal E.}, year={2018}, month={Apr}, pages={791–806} } @article{carpenter_griffey_malla_barnett_marshall_fountain_murphy_milus_johnson_buck_et al._2017, title={Identification of Quantitative Resistance to Puccinia striiformis and Puccina triticinia in the Soft Red Winter Wheat Cultivar 'Jamestown'}, volume={57}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2017.03.0143}, abstractNote={Disease resistance is critical in soft red winter wheat (Triticum aestivum L.) cultivars. Leaf rust caused by Puccinia triticina Eriks and stripe rust caused by Puccinia striiformis Westend. f. sp. tritici Eriks. are destructive pathogens of wheat. Phenotypic data were collected at diverse locations for resistance to leaf rust (North Carolina, Texas, and Virginia) and stripe rust (Arkansas, North Carolina, Georgia, Texas, and Virginia) in a Pioneer ‘25R47’ /‘Jamestown’ (P47/JT) population composed of 186 F5:9 recombinant inbred lines (RILs). The P47/JT RILs were genotyped with a public 90K iSelect single‐nucleotide polymorphism array. Analysis of the P47/JT population identified two quantitative trait loci (QTL) for leaf rust resistance on chromosome 5B and two QTL for stripe rust resistance on chromosomes 3B and 6A. These QTL were associated with both infection type and disease severity. Phenotypic variation (%) explained by the putative leaf rust resistance QTL of Jamestown on 5B was as high as 22.1%. Variation explained by the putative stripe rust resistance QTL of Jamestown on 3B and 6A was as high as 11.1 and 14.3%, respectively. Introgression and pyramiding of these QTL with other genes conferring resistance to leaf and stripe rusts via marker‐assisted selection will facilitate development of soft red winter wheat cultivars having more durable resistance.}, number={6}, journal={CROP SCIENCE}, author={Carpenter, Neal R. and Griffey, Carl A. and Malla, Subas and Barnett, Marla and Marshall, David and Fountain, Myron O. and Murphy, J. Paul and Milus, Eugene and Johnson, Jerry and Buck, James and et al.}, year={2017}, pages={2991–3001} } @article{petersen_lyerly_mckendry_islam_brown-guedira_cowger_dong_murphy_2017, title={Validation of Fusarium Head Blight Resistance QTL in US Winter Wheat}, volume={57}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2015.07.0415}, abstractNote={Fusarium head blight (FHB), primarily caused by Fusarium graminearum Schwabe [telemorph: Gibberella zeae Schw. (Petch)], can significantly reduce the grain quality of wheat (Triticum aestivum L.) due to mycotoxin contamination. Two US soft red winter wheat cultivars, Bess and NC‐Neuse, have moderate resistance to FHB. The objective of this study was to validate genomic regions associated with FHB resistance identified in previous studies involving NC‐Neuse and the cultivar Truman, a full‐sib of Bess. A total of 98 doubled haploid lines derived from the cross Bess × NC‐Neuse were evaluated in inoculated, mist‐irrigated field nurseries. The lines were evaluated for FHB incidence, severity, Fusarium‐damaged kernels, and deoxynivalenol content in seven environments between 2011 and 2014. A 3338‐cM linkage map was developed based on 4014 simple sequence repeat and single nucleotide polymorphism markers. Twelve quantitative trait loci (QTL) associated with FHB resistance were identified. NC‐Neuse alleles provided resistance at QTL on five chromosomes and Bess alleles provided resistance at QTL on five other chromosomes. Alignment of linkage maps revealed that five of these QTL were overlapping with previously identified regions. Quantitative trait loci on chromosomes 1A, 4A, and 6A identified in this study overlapped with QTL regions identified in NC‐Neuse, and QTL identified on chromosomes 2B and 3B overlapped with QTL regions identified in Truman. A preliminary test using Kompetitive Allele‐Specific polymerase chain reaction assays on recent Uniform Southern Winter Wheat Scab Nursery entries showed that the assays developed for Qfhb.nc‐2B.1 may be good candidates for use in marker‐assisted selection.}, number={1}, journal={CROP SCIENCE}, author={Petersen, Stine and Lyerly, Jeanette H. and McKendry, Anne L. and Islam, M. Sariful and Brown-Guedira, Gina and Cowger, Christina and Dong, Yanhong and Murphy, J. Paul}, year={2017}, pages={1–12} } @article{livingston_tuong_isleib_murphy_2016, title={Differences between wheat genotypes in damage from freezing temperatures during reproductive growth}, volume={74}, ISSN={["1873-7331"]}, DOI={10.1016/j.eja.2015.12.002}, abstractNote={Cereal crops in the reproductive stage of growth are considerably more susceptible to injury from freezing temperatures than during their vegetative growth stage in the fall. While damage resulting from spring-freeze events has been documented, information on genotypic differences in tolerance to spring-freezes is scarce. Ninety wheat genotypes were subjected to a simulated spring-freeze at the mid-boot growth stage under controlled conditions. Spring-freeze tolerance was evaluated as the number of seeds per head at maturity after plants were frozen at −6 °C. Plants that froze, as confirmed by infrared (IR) thermography, died shortly after thawing and consequently the heads did not mature. Only in plants that had no visible freezing (super-cooled) were heads able to reach maturity and produce seeds. In plants that super-cooled four genotypes had significantly higher seed counts after being exposed to freezing than three with the lowest. In addition, significant differences between genotypes were found in whole plant survival among those that had frozen. Genotypes with high whole-plant freezing survival were not necessarily the same as the super-cooled plants with the highest seed counts. Spring-freeze tolerance was not correlated with maturity suggesting that improvement in freezing tolerance could be selected for without affecting heading date. Spring-freeze tolerance was not correlated with freezing tolerance of genotypes of plants in a vegetative state, either under non-acclimated or cold-acclimated conditions indicating that vegetative freezing tolerance is not a good predictor of spring-freeze tolerance.}, journal={EUROPEAN JOURNAL OF AGRONOMY}, author={Livingston, David P., III and Tuong, Tan D. and Isleib, Thomas G. and Murphy, J. Paul}, year={2016}, month={Mar}, pages={164–172} } @article{petersen_lyerly_maloney_brown-guedira_cowger_costa_dong_murphy_2016, title={Mapping of Fusarium Head Blight Resistance Quantitative Trait Loci in Winter Wheat Cultivar NC-Neuse}, volume={56}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2015.05.0312}, abstractNote={Fusarium head blight (FHB), primarily caused by Fusarium graminearum, can significantly reduce the grain quality of wheat (Triticum aestivum L.) due to mycotoxin contamination. The objective of this study was to identify quantitative trait loci (QTL) for FHB resistance in the moderately resistant soft red winter wheat cultivar NC‐Neuse. A total of 170 recombinant inbred lines (RILs) from a cross between NC‐Neuse and the susceptible cultivar AGS 2000 were evaluated in inoculated, mist‐irrigated field nurseries. The lines were evaluated for FHB incidence (INC), severity (SEV), Fusarium‐damaged kernels (FDK), and deoxynivalenol (DON) content in seven environments between 2011 and 2014. A 3,419 cM linkage map was developed based on 1839 simple sequence repeat (SSR), diversity array technology (DArT), and single nucleotide polymorphism (SNP) markers. Seven FHB resistance QTL on chromosomes 1A, 1B, 1D, 2A, 4A, 5B, and 6A were mapped. The QTL alleles conferring resistance on 1A, 1B, 2A, 4A, and 6A originated from NC‐Neuse, while the alleles associated with resistance on 1D and 5B originated from AGS 2000. Quantitative trait loci effects ranged from 9 to 12% for INC, from 6 to 11% for SEV, from 8 to 20% for FDK, and from 6 to 18% for DON. The QTL on 5B co‐localized with the Vrn‐B1 locus. Kompetitive Allele‐Specific PCR (KASP) assays were developed for each NC‐Neuse QTL region. A preliminary test using these assays on recent Uniform Southern Winter Wheat Nursery (USWWN) entries indicated Qfhb.nc‐1A, Qfhb.nc‐1B, and Qfhb.nc‐6A as likely the best candidates for use in marker‐assisted selection.}, number={4}, journal={CROP SCIENCE}, author={Petersen, Stine and Lyerly, Jeanette H. and Maloney, Peter V. and Brown-Guedira, Gina and Cowger, Christina and Costa, Jose M. and Dong, Yanhong and Murphy, J. Paul}, year={2016}, pages={1473–1483} } @article{klos_huang_bekele_obert_babiker_beattie_bjornstad_bonman_carson_chao_et al._2016, title={Population Genomics Related to Adaptation in Elite Oat Germplasm}, volume={9}, ISSN={["1940-3372"]}, DOI={10.3835/plantgenome2015.10.0103}, abstractNote={Six hundred thirty five oat (Avena sativa L.) lines and 4561 single‐nucleotide polymorphism (SNP) loci were used to evaluate population structure, linkage disequilibrium (LD), and genotype–phenotype association with heading date. The first five principal components (PCs) accounted for 25.3% of genetic variation. Neither the eigenvalues of the first 25 PCs nor the cross‐validation errors from K = 1 to 20 model‐based analyses suggested a structured population. However, the PC and K = 2 model‐based analyses supported clustering of lines on spring oat vs. southern United States origin, accounting for 16% of genetic variation (p < 0.0001). Single‐locus F‐statistic (FST) in the highest 1% of the distribution suggested linkage groups that may be differentiated between the two population subgroups. Population structure and kinship‐corrected LD of r2 = 0.10 was observed at an average pairwise distance of 0.44 cM (0.71 and 2.64 cM within spring and southern oat, respectively). On most linkage groups LD decay was slower within southern lines than within the spring lines. A notable exception was found on linkage group Mrg28, where LD decay was substantially slower in the spring subpopulation. It is speculated that this may be caused by a heterogeneous translocation event on this chromosome. Association with heading date was most consistent across location‐years on linkage groups Mrg02, Mrg12, Mrg13, and Mrg24.}, number={2}, journal={PLANT GENOME}, author={Klos, Kathy Esvelt and Huang, Yung-Fen and Bekele, Wubishet A. and Obert, Don E. and Babiker, Ebrahiem and Beattie, Aaron D. and Bjornstad, Asmund and Bonman, J. Michael and Carson, Martin L. and Chao, Shiaoman and et al.}, year={2016}, month={Jul} } @article{cowger_weisz_arellano_murphy_2016, title={Profitability of Integrated Management of Fusarium Head Blight in North Carolina Winter Wheat}, volume={106}, ISSN={["1943-7684"]}, DOI={10.1094/phyto-10-15-0263-r}, abstractNote={ Fusarium head blight (FHB) is one of the most difficult small-grain diseases to manage, due to the partial effectiveness of management techniques and the narrow window of time in which to apply fungicides profitably. The most effective management approach is to integrate cultivar resistance with FHB-specific fungicide applications; yet, when forecasted risk is intermediate, it is often unclear whether such an application will be profitable. To model the profitability of FHB management under varying conditions, we conducted a 2-year split-plot field experiment having as main plots high-yielding soft red winter wheat cultivars, four moderately resistant (MR) and three susceptible (S) to FHB. Subplots were sprayed at flowering with Prosaro or Caramba, or left untreated. The experiment was planted in seven North Carolina environments (location–year combinations); three were irrigated to promote FHB development and four were not irrigated. Response variables were yield, test weight, disease incidence, disease severity, deoxynivalenol (DON), Fusarium-damaged kernels, and percent infected kernels. Partial profits were compared in two ways: first, across low-, medium-, or high-DON environments; and second, across environment–cultivar combinations divided by risk forecast into “do spray” and “do not spray” categories. After surveying DON and test weight dockage among 21 North Carolina wheat purchasers, three typical market scenarios were used for modeling profitability: feed-wheat, flexible (feed or flour), and the flour market. A major finding was that, on average, MR cultivars were at least as profitable as S cultivars, regardless of epidemic severity or market. Fungicides were profitable in the feed-grain and flexible markets when DON was high, with MR cultivars in the flexible or flour markets when DON was intermediate, and on S cultivars aimed at the flexible market. The flour market was only profitable when FHB was present if DON levels were intermediate and cultivar resistance was combined with a fungicide. It proved impossible to use the risk forecast to predict profitability of fungicide application. Overall, the results indicated that cultivar resistance to FHB was important for profitability, an FHB-targeted fungicide expanded market options when risk was moderate or high, and the efficacy of fungicide decision-making is reduced by factors that limit the accuracy of risk forecasts. }, number={8}, journal={PHYTOPATHOLOGY}, author={Cowger, Christina and Weisz, Randy and Arellano, Consuelo and Murphy, Paul}, year={2016}, month={Aug}, pages={814–823} } @article{babar_blount_barnett_mackowiak_akond_harrison_johnson_mergoum_mason_murphy_et al._2017, title={Registration of 'FL720' Oat}, volume={11}, ISSN={["1940-3496"]}, DOI={10.3198/jpr2016.04.0025crc}, abstractNote={FL720 (Reg. No. CV‐380, PI 678418), a facultative‐type forage oat (Avena sativa L.), was co‐developed by the University of Florida and Louisiana State University Agricultural Center and was released in 2014. FL720 was tested under the experimental designation FL0720‐R6. This line was derived from the three‐way cross FL0206FSB‐34‐S1//FL0016‐H1/IL 3555. FL720 was developed using selected bulk breeding method and was selected as an F5:6 head row. The line was evaluated in preliminary, advanced, and regional forage and grain yield trials from 2012 to 2015. It is a mid‐maturing, high‐yielding forage cultivar with excellent potential for early fall forage production. FL720 was observed to be uniform and stable across multiple locations from 2011 to present. FL720 possess a semiprostrate growth habit and tall plant type. The leaves are large and light green in color. The panicles are long with an average of 4.0 seed whorls. FL720 possesses excellent crown rust (CR) and Barley yellow dwarf virus resistance and moderate resistance to stem rust. FL720 is resistant to the prevalent CR virulence combination that has caused significant disease on the most commonly grown oat cultivars across the southeastern United States since 2013. Average late fall and winter forage yield of FL720 was higher than ‘LA99016’ and was similar to that cultivar in early spring forage production. FL720 has broad environmental adaptation and has performed well in trials conducted in Florida, southern Georgia, Louisiana, Texas, and South Carolina.}, number={1}, journal={JOURNAL OF PLANT REGISTRATIONS}, author={Babar, M. A. and Blount, A. R. and Barnett, R. R. and Mackowiak, C. and Akond, M. and Harrison, S. A. and Johnson, J. W. and Mergoum, M. and Mason, E. and Murphy, P. and et al.}, year={2017}, month={Jan}, pages={15–19} } @article{holland_graham_murphy_lynn_2015, title={Charles W. Stuber: Maize Geneticist and Pioneer of Marker-Assisted Selection}, volume={39}, DOI={10.1002/9781119107743.ch1}, abstractNote={This chapter contains sections titled: BIOGRAPHICAL SKETCH SCIENTIFIC ACHIEVEMENTS LEADERSHIP BEFORE AND AFTER RETIREMENT AWARDS AND HONORS IMPACT ON BREEDING PARADIGMS IN THE PRIVATE SECTOR IMPACT ON STUDENTS AND POSTDOCS}, journal={Plant breeding reviews, vol 39}, author={Holland, James and Graham, G. I. and Murphy, J. P. and Lynn, M.}, year={2015}, pages={1–22} } @article{cabrera_guttieri_smith_souza_sturbaum_hua_griffey_barnett_murphy_ohm_et al._2015, title={Identification of milling and baking quality QTL in multiple soft wheat mapping populations}, volume={128}, ISSN={["1432-2242"]}, DOI={10.1007/s00122-015-2580-3}, abstractNote={Two mapping approaches were use to identify and validate milling and baking quality QTL in soft wheat. Two LG were consistently found important for multiple traits and we recommend the use marker-assisted selection on specific markers reported here. Wheat-derived food products require a range of characteristics. Identification and understanding of the genetic components controlling end-use quality of wheat is important for crop improvement. We assessed the underlying genetics controlling specific milling and baking quality parameters of soft wheat including flour yield, softness equivalent, flour protein, sucrose, sodium carbonate, water absorption and lactic acid, solvent retention capacities in a diversity panel and five bi-parental mapping populations. The populations were genotyped with SSR and DArT markers, with markers specific for the 1BL.1RS translocation and sucrose synthase gene. Association analysis and composite interval mapping were performed to identify quantitative trait loci (QTL). High heritability was observed for each of the traits evaluated, trait correlations were consistent over populations, and transgressive segregants were common in all bi-parental populations. A total of 26 regions were identified as potential QTL in the diversity panel and 74 QTL were identified across all five bi-parental mapping populations. Collinearity of QTL from chromosomes 1B and 2B was observed across mapping populations and was consistent with results from the association analysis in the diversity panel. Multiple regression analysis showed the importance of the two 1B and 2B regions and marker-assisted selection for the favorable alleles at these regions should improve quality.}, number={11}, journal={THEORETICAL AND APPLIED GENETICS}, author={Cabrera, Antonio and Guttieri, Mary and Smith, Nathan and Souza, Edward and Sturbaum, Anne and Hua, Duc and Griffey, Carl and Barnett, Marla and Murphy, Paul and Ohm, Herb and et al.}, year={2015}, month={Nov}, pages={2227–2242} } @article{worthington_reberg-horton_brown-guedira_jordan_weisz_murphy_2015, title={Relative Contributions of Allelopathy and Competitive Traits to the Weed Suppressive Ability of Winter Wheat Lines Against Italian Ryegrass}, volume={55}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2014.02.0150}, abstractNote={ABSTRACTAllelopathy and competitive ability have been identified as independent factors contributing to the weed suppressive ability of crop cultivars; however, it is not clear whether these factors have equal influence on weed suppression outcomes of winter wheat (Triticum aestivum L.) lines in the field. Fifty‐eight winter wheat lines adapted to the southeastern United States were screened for allelopathic activity against Italian ryegrass (Lolium perenne L. ssp. multiflorum [Lam.] Husnot) in an agar‐based seedling bioassay. Eight strongly and weakly allelopathic lines were identified and evaluated for weed suppressive ability and grain yield tolerance in a replicated field experiment conducted in North Carolina. Significant genotypic differences in weed suppressive ability were found in three of four study environments, while genotypic differences in yield tolerance were identified in all environments. Although the allelopathic activity of genotypes varied in the seedling bioassay, no correlations between allelopathy and weed suppressive ability or grain yield tolerance were observed. Weed suppressive ability was correlated with competitive traits, including vigor and erect growth habit during tillering (Zadoks GS 29), high leaf area index (LAI) at stem extension (GS 31), plant height at tillering and stem extension (GS 29, 31), grain yield in weedy conditions, and grain yield tolerance. Therefore, breeders in the southeastern United States should focus their efforts on improving competitive traits within adapted germplasm rather than selecting for cultivars with high allelopathic activity to achieve maximum gains in weed suppressive ability against Italian ryegrass.}, number={1}, journal={CROP SCIENCE}, publisher={Crop Science Society of America}, author={Worthington, Margaret and Reberg-Horton, S. Chris and Brown-Guedira, Gina and Jordan, David and Weisz, Randy and Murphy, J. Paul}, year={2015}, pages={57–64} } @article{maloney_petersen_navarro_marshall_mckendry_costa_murphy_2014, title={Digital Image Analysis Method for Estimation of Fusarium-Damaged Kernels in Wheat}, volume={54}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2013.07.0432}, abstractNote={ABSTRACTFusarium head blight (FHB) of wheat (Triticum aestivum L.), or head scab, causes a reduction in grain yield and quality through the formation of shriveled, dull‐grey seeds called “tombstones” or Fusarium‐damaged kernels (FDK). Fusarium‐damaged kernels are commonly quantified on a percentage basis by visually separating damaged from healthy kernels following harvest, in a process that is both time consuming and labor intensive. The objective of this study was to evaluate an alternative method for quantifying FDK through the use of the digital image analysis program ImageJ. The ‘NC‐Neuse’ × ‘AGS 2000’ F5–derived recombinant inbred population of 172 lines and the NC‐Neuse בBess’ double haploid population of 112 lines were used in this study. NC‐Neuse and Bess were moderately resistant and AGS 2000 was susceptible to FHB. The populations were evaluated under moderate to heavy FHB epidemics in a total of five environments in North Carolina, Maryland, and Missouri with two to three replications per environment during the 2010 to 2011 and 2011 to 2012 seasons. Following hand harvest and grain processing, FDK was estimated by (i) visual separation of diseased kernels and (ii) digital image analysis using ImageJ on captured images of grain samples. The correlation between the two methods ranged from 0.72 to 0.80 over five environments. A lower correlation was observed in one environment due to cracked and broken kernels in the samples. Digital image analysis was three times faster than the visual method and estimated FDK on a larger scale per plot sample, whereas labor and time constraints limited the sample size for the visual method. Digital image analysis was consistent over samples and appears well suited as an alternative form to estimate percent of FDK in grain that is not damaged in other ways.}, number={5}, journal={CROP SCIENCE}, author={Maloney, Peter V. and Petersen, Stine and Navarro, Rene A. and Marshall, David and McKendry, Anne L. and Costa, Jose M. and Murphy, J. Paul}, year={2014}, pages={2077–2083} } @article{petersen_lyerly_worthington_parks_cowger_marshall_brown-guedira_murphy_2015, title={Mapping of powdery mildew resistance gene Pm53 introgressed from Aegilops speltoides into soft red winter wheat}, volume={128}, ISSN={["1432-2242"]}, DOI={10.1007/s00122-014-2430-8}, abstractNote={A powdery mildew resistance gene was introgressed from Aegilops speltoides into winter wheat and mapped to chromosome 5BL. Closely linked markers will permit marker-assisted selection for the resistance gene. Powdery mildew of wheat (Triticum aestivum L.) is a major fungal disease in many areas of the world, caused by Blumeria graminis f. sp. tritici (Bgt). Host plant resistance is the preferred form of disease prevention because it is both economical and environmentally sound. Identification of new resistance sources and closely linked markers enable breeders to utilize these new sources in marker-assisted selection as well as in gene pyramiding. Aegilops speltoides (2n = 2x = 14, genome SS), has been a valuable disease resistance donor. The powdery mildew resistant wheat germplasm line NC09BGTS16 (NC-S16) was developed by backcrossing an Ae. speltoides accession, TAU829, to the susceptible soft red winter wheat cultivar 'Saluda'. NC-S16 was crossed to the susceptible cultivar 'Coker 68-15' to develop F2:3 families for gene mapping. Greenhouse and field evaluations of these F2:3 families indicated that a single gene, designated Pm53, conferred resistance to powdery mildew. Bulked segregant analysis showed that multiple simple sequence repeat (SSR) and single nucleotide polymorphism (SNP) markers specific to chromosome 5BL segregated with the resistance gene. The gene was flanked by markers Xgwm499, Xwmc759, IWA6024 (0.7 cM proximal) and IWA2454 (1.8 cM distal). Pm36, derived from a different wild wheat relative (T. turgidum var. dicoccoides), had previously been mapped to chromosome 5BL in a durum wheat line. Detached leaf tests revealed that NC-S16 and a genotype carrying Pm36 differed in their responses to each of three Bgt isolates. Pm53 therefore appears to be a new source of powdery mildew resistance.}, number={2}, journal={THEORETICAL AND APPLIED GENETICS}, author={Petersen, Stine and Lyerly, Jeanette H. and Worthington, Margaret L. and Parks, Wesley R. and Cowger, Christina and Marshall, David S. and Brown-Guedira, Gina and Murphy, J. Paul}, year={2015}, month={Feb}, pages={303–312} } @article{worthington_lyerly_petersen_brown-guedira_marshall_cowger_parks_murphy_2014, title={MlUM15: an Aegilops neglecta-derived powdery mildew resistance gene in common wheat}, volume={54}, number={4}, journal={Crop Science}, author={Worthington, M. and Lyerly, J. and Petersen, S. and Brown-Guedira, G. and Marshall, D. and Cowger, C. and Parks, R. and Murphy, J. P.}, year={2014}, pages={1397–1406} } @article{hao_parks_cowger_chen_wang_bland_murphy_guedira_brown-guedira_johnson_et al._2015, title={Molecular characterization of a new powdery mildew resistance gene Pm54 in soft red winter wheat}, volume={128}, ISSN={["1432-2242"]}, DOI={10.1007/s00122-014-2445-1}, abstractNote={A new powdery mildew resistance gene Pm54 was identified on chromosome 6BL in soft red winter wheat. Powdery mildew is causing increasing damage to wheat production in the southeastern USA. To combat the disease, a continuing need exists to discover new genes for powdery mildew resistance and to incorporate those genes into breeding programs. Pioneer(®) variety 26R61 (shortened as 26R61) and AGS 2000 have been used as checks in the Uniform Southern Soft Red Winter Wheat Nursery for a decade, and both have provided good resistance across regions during that time. In the present study, a genetic analysis of mildew resistance was conducted on a RIL population developed from a cross of 26R61 and AGS 2000. Phenotypic evaluation was conducted in the field at Plains, GA, and Raleigh, NC, in 2012 and 2013, a total of four environments. Three quantitative trait loci (QTL) with major effect were consistently detected on wheat chromosomes 2BL, 4A and 6BL. The 2BL QTL contributed by 26R61 was different from Pm6, a widely used gene in the southeastern USA. The other two QTL were identified from AGS 2000. The 6BL QTL was subsequently characterized as a simple Mendelian factor when the population was inoculated with a single Blumeria graminis f. sp. tritici (Bgt) isolate in controlled environments. Since there is no known powdery mildew resistance gene (Pm) on this particular location of common wheat, the gene was designated Pm54. The closely linked marker Xbarc134 was highly polymorphic in a set of mildew differentials, indicating that the marker should be useful for pyramiding Pm54 with other Pm genes by marker-assisted selection.}, number={3}, journal={THEORETICAL AND APPLIED GENETICS}, author={Hao, Y. F. and Parks, R. and Cowger, C. and Chen, Z. B. and Wang, Y. Y. and Bland, D. and Murphy, J. P. and Guedira, M. and Brown-Guedira, Gina and Johnson, J. and et al.}, year={2015}, month={Mar}, pages={465–476} } @article{worthington_reberg-horton_brown-guedira_jordan_weisz_murphy_2015, title={Morphological Traits Associated with Weed-Suppressive Ability of Winter Wheat against Italian Ryegrass}, volume={55}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2014.02.0149}, abstractNote={ABSTRACTWeed‐suppressive wheat (Triticum aestivum L.) cultivars have been suggested as a complement to chemical and cultural methods of weed control. The objectives of this study were to assess the range of weed‐suppressive ability against Italian ryegrass [Lolium perenne L. ssp. multiflorum (Lam.) Husnot] existing in winter wheat lines adapted to North Carolina and to identify wheat morphological traits that could facilitate indirect selection for weed suppression in the southeastern United States. Fifty‐three commercially available cultivars and advanced experimental lines were overseeded with a uniform, high rate of Italian ryegrass, evaluated for various morphological traits throughout the growing season, and investigated for weed‐suppressive ability at a total of four field sites. Genotypic differences in Italian ryegrass seed head density (P ≤ 0.05) were detected among the wheat lines. Reduced Italian ryegrass seed head density was correlated (P ≤ 0.05) with high vigor during tillering and heading (Zadoks growth stage [GS] 25, 29, 55), erect growth habit (GS 29), low normalized difference vegetation index (NDVI) (GS 29), high leaf area index (LAI) at stem extension (GS 31), early heading date, and tall height throughout the growing season (GS 29, 31, 55, 70 to 80) in three of four sites. Multiple regression models show that 71% of variation in weed‐suppressive ability was accounted for by final height (GS 70 to 80) and either height or plant vigor at late tillering (GS 29). Thus, breeders could improve weed‐suppressive ability using weighted index selection for genotypes that are tall or vigorous during tillering with tall final height.}, number={1}, journal={CROP SCIENCE}, publisher={Crop Science Society of America}, author={Worthington, Margaret and Reberg-Horton, S. Chris and Brown-Guedira, Gina and Jordan, David and Weisz, Randy and Murphy, J. Paul}, year={2015}, pages={50–56} } @article{clark_costa_griffey_brown-guedira_dong_souza_murphy_van sanford_2014, title={Registration of Scab-Resistant KY06C-11-3-10 Soft Red Winter Wheat Germplasm}, volume={8}, ISSN={["1940-3496"]}, DOI={10.3198/jpr2013.07.0039crg}, abstractNote={Copyright © Crop Science Society of America. All rights reserved. No part of this periodical may be reproduced or trans mitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Permission for printing and for reprinting the material contained herein has been obtained by the publisher.}, number={2}, journal={JOURNAL OF PLANT REGISTRATIONS}, author={Clark, Anthony J. and Costa, Jose M. and Griffey, Carl A. and Brown-Guedira, Gina L. and Dong, Yanhong and Souza, Edward J. and Murphy, J. Paul and Van Sanford, David A.}, year={2014}, month={May}, pages={211–216} } @article{worthington_reberg-horton_jordan_murphy_2013, title={A Comparison of Methods for Evaluating the Suppressive Ability of Winter Wheat Cultivars against Italian Ryegrass (Lolium perenne)}, volume={61}, ISSN={["1550-2759"]}, DOI={10.1614/ws-d-12-00167.1}, abstractNote={Infestations of Italian ryegrass are problematic in both conventional and organic wheat production systems. The development of wheat cultivars with superior competitive ability against Italian ryegrass could play a role in maintaining acceptable yields and suppressing weed populations. Research was conducted in North Carolina to identify indirect methods of selection for Italian ryegrass suppressive ability (hereafter referred to as weed suppressive ability) of winter wheat cultivars that correlate well with Italian ryegrass-to-wheat biomass ratios. Two winter wheat cultivars (Dyna-Gro Baldwin and Dyna-Gro Dominion) and one experimental wheat line (NC05-19684) with differing morphological traits were overseeded with varying densities of Italian ryegrass. Wheat height measured throughout the growing season in weed-free plots was strongly associated with weed suppressive ability, but high wheat tillering capacity had no significant effect on weed suppressive ability in the lines tested in this study. Italian ryegrass seed head density during grain fill was strongly correlated (r= 0.94) with Italian ryegrass-to-wheat biomass ratio, the generally accepted measure of weed suppressive ability. Visual estimates of percent Italian ryegrass biomass relative to the plot with the highest level of Italian ryegrass infestation in each replicate were also strongly correlated with weed suppressive ability at all growth stages, especially during heading (r= 0.87) (Zadoks growth stage [GS] 55). Measurements from nonimaging spectrophotometers and overhead photographs taken from tillering (Zadoks 23 to 25) to early dough development (Zadoks 80) were unreliable estimates of end-of-season Italian ryegrass-to-wheat biomass ratios because they failed to account for wheat cultivar differences in biomass, color, and growth habit. Italian ryegrass seed head density and visual estimates of Italian ryegrass biomass during grain fill are appropriate indirect methods of selection for weed suppressive ability in breeding programs.}, number={3}, journal={WEED SCIENCE}, publisher={Cambridge University Press (CUP)}, author={Worthington, Margaret L. and Reberg-Horton, S. Chris and Jordan, David and Murphy, J. Paul}, year={2013}, pages={491–499} } @article{bertucci_brown-guedira_murphy_cowger_2014, title={Genes Conferring Sensitivity to Stagonospora nodorum Necrotrophic Effectors in Stagonospora Nodorum Blotch-Susceptible US Wheat Cultivars}, volume={98}, ISSN={["1943-7692"]}, DOI={10.1094/pdis-08-13-0820-re}, abstractNote={ Stagonospora nodorum is a necrotrophic fungal pathogen that causes Stagonospora nodorum blotch (SNB), a yield- and quality-reducing disease of wheat. S. nodorum produces a set of necrotrophic effectors (NEs) that interact with the products of host sensitivity genes to cause cell death and increased susceptibility to disease. The focus of this study was determination of NE sensitivity among 25 winter wheat cultivars, many of them from the southeastern United States, that are susceptible to SNB, as well as the moderately resistant ‘NC-Neuse’. Thirty-three isolates of S. nodorum previously collected from seven southeastern U.S. states were cultured for NE production, and the culture filtrates were used in an infiltration bioassay. Control strains of Pichia pastoris that expressed SnToxA, SnTox1, or SnTox3 were also used. All SNB-susceptible cultivars were sensitive to at least one NE, while NC-Neuse was insensitive to all NEs tested. Among the sensitive lines, 32% contained sensitivity gene Tsn1 and 64% contained sensitivity gene Snn3. None were sensitive to SnTox1. Additionally, 10 molecular markers for sensitivity genes Tsn1, Snn1, Snn2, and Snn3 were evaluated for diagnostic potential. Only the marker Xfcp623 for Tsn1 was diagnostic, and it was in perfect agreement with the results of the infiltration bioassays. The results illuminate which NE sensitivity genes may be of concern in breeding for resistance to SNB in the southeastern United States. }, number={6}, journal={PLANT DISEASE}, author={Bertucci, Matthew and Brown-Guedira, Gina and Murphy, J. Paul and Cowger, Christina}, year={2014}, month={Jun}, pages={746–753} } @inproceedings{petersen_maloney_lyerly_navarro_cowger_brown-guedira_costa_murphy_2013, title={QTL Associated with Fusarium Head Blight Resistance in the NC-NEUSE X AGS 2000 Recombinant Inbred Population}, booktitle={Proceedings of the 2013 National Fusarium Head Blight Forum}, author={Petersen, S. and Maloney, P. V. and Lyerly, J. H. and Navarro, R. A. and Cowger, C. and Brown-Guedira, G. and Costa, J. M. and Murphy, J. P.}, year={2013} } @article{oliver_tinker_lazo_chao_jellen_carson_rines_obert_lutz_shackelford_et al._2013, title={SNP Discovery and Chromosome Anchoring Provide the First Physically-Anchored Hexaploid Oat Map and Reveal Synteny with Model Species}, volume={8}, ISSN={["1932-6203"]}, DOI={10.1371/journal.pone.0058068}, abstractNote={A physically anchored consensus map is foundational to modern genomics research; however, construction of such a map in oat (Avena sativa L., 2n = 6x = 42) has been hindered by the size and complexity of the genome, the scarcity of robust molecular markers, and the lack of aneuploid stocks. Resources developed in this study include a modified SNP discovery method for complex genomes, a diverse set of oat SNP markers, and a novel chromosome-deficient SNP anchoring strategy. These resources were applied to build the first complete, physically-anchored consensus map of hexaploid oat. Approximately 11,000 high-confidence in silico SNPs were discovered based on nine million inter-varietal sequence reads of genomic and cDNA origin. GoldenGate genotyping of 3,072 SNP assays yielded 1,311 robust markers, of which 985 were mapped in 390 recombinant-inbred lines from six bi-parental mapping populations ranging in size from 49 to 97 progeny. The consensus map included 985 SNPs and 68 previously-published markers, resolving 21 linkage groups with a total map distance of 1,838.8 cM. Consensus linkage groups were assigned to 21 chromosomes using SNP deletion analysis of chromosome-deficient monosomic hybrid stocks. Alignments with sequenced genomes of rice and Brachypodium provide evidence for extensive conservation of genomic regions, and renewed encouragement for orthology-based genomic discovery in this important hexaploid species. These results also provide a framework for high-resolution genetic analysis in oat, and a model for marker development and map construction in other species with complex genomes and limited resources.}, number={3}, journal={PLOS ONE}, author={Oliver, Rebekah E. and Tinker, Nicholas A. and Lazo, Gerard R. and Chao, Shiaoman and Jellen, Eric N. and Carson, Martin L. and Rines, Howard W. and Obert, Donald E. and Lutz, Joseph D. and Shackelford, Irene and et al.}, year={2013}, month={Mar} } @article{benson_brown-guedira_murphy_sneller_2012, title={Population Structure, Linkage Disequilibrium, and Genetic Diversity in Soft Winter Wheat Enriched for Fusarium Head Blight Resistance}, volume={5}, ISSN={["1940-3372"]}, DOI={10.3835/plantgenome2011.11.0027}, abstractNote={The occurrence of epidemics of Fusarium head blight (FHB), caused by Fusarium graminearum Schwabe, in U.S. winter wheat (Triticum aestivum L.) during the past two decades led to significant emphasis on development of resistant cultivars. Understanding the genetic diversity, population structure (PS), and linkage disequilibrium (LD) in winter wheat in the eastern United States is important for marker‐assisted breeding and association analysis in this germplasm. Lines selected from collaborative FHB screening nurseries were genotyped with simple sequence repeat (SSR), sequence tagged site (STS), and Diversity Array Technology (DArT) markers to assess LD, genetic diversity, and PS. The genomewide average of LD decay to r2 < 0.2 was 9.9 cM and moderate levels of LD (r2 > 0.2) were generally constrained to markers less than 5 cM apart. Although the lines evaluated were targeted to distinct production zones of the eastern winter wheat region, cluster and principal component analyses did not detect separation of lines into subpopulations. The short, intense breeding history for scab resistance may have localized effects on LD. Lack of subgroups within our population could be due to intercrossing among common resistant parents and indicate frequent admixture and germplasm exchange among U.S. winter wheat programs focused on development of FHB resistant cultivars.}, number={2}, journal={PLANT GENOME}, author={Benson, Jared and Brown-Guedira, Gina and Murphy, J. Paul and Sneller, Clay}, year={2012}, month={Jul}, pages={71–80} } @article{chen_griffey_liu_maroof_murphy_navarro_sneller_brown-guedira_souza_2012, title={Registration of Fusarium Head Blight-Resistant Soft Red Winter Wheat Germplasm VA04W-433 and VA04W-474}, volume={6}, ISSN={["1936-5209"]}, DOI={10.3198/jpr2011.07.0397crg}, abstractNote={Fusarium head blight [FHB; caused by Fusarium graminearum Schwabe; telomorph Gibberella zeae (Schwein.) Petch] is one of the major diseases of winter wheat (Triticum aestivum L.) in the U.S. mid‐Atlantic region. The objective of this research was to develop adapted soft red winter (SRW) wheat germplasm having enhanced resistance to FHB for this region. The SRW wheat germplasm lines VA04W‐433 (Reg. No. GP‐943, PI 657945) and VA04W‐474 (Reg. No. GP‐944, PI 657946) are two adapted FHB‐resistant lines developed by the Virginia Agricultural Experiment Station and released in 2009. VA04W‐433 was derived from a three‐way cross of ‘Ning 7840’/Pioneer brand ‘2684’//VA96‐54‐244. VA04W‐474 is a doubled haploid line derived from the F1 of the three‐way cross ‘Roane’//W14/‘Coker 9134’ using a wheat‐by‐maize hybridization method. The resistance was derived from known Chinese resistance sources Ning 7840, in VA04W‐433 and, W14, in VA04W‐474 and selected through intensive phenotypic screening. The resistance was confirmed with molecular markers on chromosome 3BS and 5AS. Both lines have better grain volume weight, better resistance to deoxynivalenol accumulation caused by FHB infection, and better resistance to leaf rust (caused by Puccinia triticina Eriks.) than the resistant check ‘Ernie’.}, number={1}, journal={JOURNAL OF PLANT REGISTRATIONS}, author={Chen, Jianli and Griffey, Carl A. and Liu, Shuyu and Maroof, M. A. Saghai and Murphy, J. Paul and Navarro, Rene A. and Sneller, Clay H. and Brown-Guedira, Gina. L. and Souza, Edward J.}, year={2012}, month={Jan}, pages={111–116} } @article{brooks_danehower_murphy_reberg-horton_burton_2012, title={Estimation of heritability of benzoxazinoid production in rye (Secale cereale) using gas chromatographic analysis}, volume={131}, ISSN={["1439-0523"]}, DOI={10.1111/j.1439-0523.2011.01885.x}, abstractNote={With 4 tablesAbstractThe 2,4‐dihydroxy‐1,4‐benzoxazin‐3‐one (DIBOA) content of Secale cereale is strongly associated with allelopathy. This has led to interest in developing allelopathic cultivars with increased DIBOA to improve weed control in this important cover crop. Objectives of this study were to determine heritability estimates for DIBOA in rye and determine the utility of gas chromatography (GC) as a screening tool in a rye allelopathy breeding programme. A synthetic population of half‐sib families varying in production of DIBOA was analysed. DIBOA concentrations ranged from 0.52 to 1.15 mg/g dwt tissue (mean = 0.70 mg/g dwt). Analysis of variance indicated significant variability for DIBOA content in rye harvested at the flag leaf stage. Year × location × genotype and block (year × location) interactions were also significant. Several genotypes were consistently ‘high’ or ‘low’ DIBOA producers across all locations and years. Narrow sense heritability estimates were 0.18 ± 0.04 SE on a per plot basis and 0.57 ± 0.07 SE on an entry mean basis. GC analysis was determined to be a good system for moderate throughput screening of lines.}, number={1}, journal={PLANT BREEDING}, publisher={Wiley}, author={Brooks, Ashley M. and Danehower, David A. and Murphy, J. Paul and Reberg-Horton, S. Chris and Burton, James D.}, year={2012}, month={Feb}, pages={104–109} } @article{kang_clark_van sanford_griffey_brown-guedira_dong_murphy_costa_2011, title={Exotic Scab Resistance Quantitative Trait Loci Effects on Soft Red Winter Wheat}, volume={51}, ISSN={["0011-183X"]}, DOI={10.2135/cropsci2010.06.0313}, abstractNote={ABSTRACTFusarium head blight (FHB), caused by Fusarium graminearum, of wheat (Triticum aestivum L.) is a disease that periodically strikes the mid‐Atlantic region of the United States. Breeding for resistant wheat varieties is an effective method of disease control. The objective of this study was to evaluate the effects of exotic FHB resistance quantitative trait loci (QTL), singly and in combination, on FHB resistance in soft red winter wheat (SRWW). Three FHB resistance QTL on chromosomes 3BS (Fhb1), 2D, and 5A were introgressed from nonadapted Chinese cultivar Ning7840 into the adapted SRWW cultivar McCormick. Eight near‐isogenic lines (NIL) were developed by marker‐assisted backcrossing. The NIL that combined 3BS and 2DL expressed the highest resistance and lowest deoxynivalenol (DON) content in four environments that included three field and one greenhouse studies. These results indicate that the combination of just two QTL (3BS and 2DL) would be useful to breed for improved FHB resistance in SRWW in the mid‐Atlantic region.}, number={3}, journal={CROP SCIENCE}, author={Kang, Jing and Clark, Anthony and Van Sanford, David and Griffey, Carl and Brown-Guedira, Gina and Dong, Yanhong and Murphy, J. Paul and Costa, Jose}, year={2011}, month={May}, pages={924–933} } @article{maloney_lyerly_wooten_anderson_livingston_brown-guedira_marshall_murphy_2011, title={Marker Development and Quantitative Trait Loci in a Fall-Sown Oat Recombinant Inbred Population}, volume={51}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2010.04.0224}, abstractNote={ABSTRACTMarker‐assisted selection for improved winter survival in oat (Avena sativa L.) is difficult because the number of simple sequence repeat (SSR) markers available in this species is limited. The objectives of this research were to increase the number of SSR markers on the ‘Fulghum’ × ‘Norline’ recombinant inbred population genetic map and to scan for quantitative trait loci (QTL) associated with winter field survival, crown freezing tolerance, vernalization response, and heading date. New SSR markers were developed from ‘Kanota’ and ‘Ogle’ genomic DNA libraries enriched for eight microsatellite motifs. New primers were evaluated for amplification, reproducibility, and polymorphism in 11 oat lines. Simple sequence repeat markers showing high‐quality polymorphism between Fulghum and Norline were subsequently examined in 128 recombinant inbred lines. Sixty‐five new SSR, four single nucleotide polymorphism (SNP), and one cleaved amplified polymorphic sequence (CAPS) markers were added to the Fulghum × Norline linkage map. This brought the total number of markers mapped on the population to 101. Phenotypic data for winter hardiness component traits in the population were obtained in previous field and controlled chamber experiments. All previously mapped markers and new SSR markers were evaluated and QTL identified. Marker loci on linkage group FN1_3_38 accounted for multiple QTL associated with winter hardiness component traits. The addition of new SSR markers to the Fulghum × Norline map in regions with winter hardiness component trait QTL will enhance marker assisted selection for these important traits.}, number={2}, journal={CROP SCIENCE}, author={Maloney, P. V. and Lyerly, J. H. and Wooten, D. R. and Anderson, J. M. and Livingston, D. P., III and Brown-Guedira, G. and Marshall, D. and Murphy, J. P.}, year={2011}, month={Mar}, pages={490–502} } @article{griffey_thomason_pitman_beahm_gundrum_liu_chen_paling_dunaway_brooks_et al._2011, title={Registration of 'SW049029104' Wheat}, volume={5}, ISSN={["1936-5209"]}, DOI={10.3198/jpr2010.03.0146crc}, abstractNote={‘SW049029104’ (Reg. No. CV‐1053, PI 658599) soft red winter (SRW) wheat (Triticum aestivum L.) was developed and released by the Virginia Agricultural Experiment Station in March 2009. SW049029104 was derived from the cross ‘38158’ (PI 619052)/Pioneer variety 2552//‘Roane’ and was tested under the experimental number VA04W‐90. SW049029104 is a broadly adapted, high‐yielding, moderately short, semidwarf (Rht2) cultivar that is resistant to powdery mildew [caused by Blumeria graminis (DC.) E.O. Speer] and Fusarium head blight (caused by Fusarium graminearum Schwabe). In the 2009 USDA‐ARS Uniform Southern SRW Wheat Nursery conducted at 25 locations, SW049029104 ranked first among 40 entries for grain yield (4889 kg ha−1) and fourth for grain volume weight (73.2 kg hL−1). The milling and baking qualities of SW049029104 exceeded those of ‘USG 3555’ and Pioneer brand 26R61. Flour softness and cookie‐spread diameter of SW049029104 (61.5–64.8 g 100 g−1 and 18.39–18.48 cm) exceeded those of USG 3555 (57.9–61.1 g 100 g−1 and 18.09–18.21 cm) and Pioneer brand 26R61 (54.5–61.1 g 100 g−1 and 18.12–18.13 cm). While flour protein concentration of SW049029104 (8.55–8.66 g 100 g−1) was lower than that of USG 3555 (8.88–9.10 g 100 g−1) and Pioneer brand 26R61 (9.65–9.66 g 100 g−1), its gluten strength, assessed via lactic acid solvent retention capacity (124.7–129.7 g 100 g−1), exceeded that of USG 3555 (118.9–124.0 g 100 g−1) and Pioneer brand 26R61 (113.5–126.0 g 100 g−1).}, number={1}, journal={JOURNAL OF PLANT REGISTRATIONS}, author={Griffey, C. A. and Thomason, W. E. and Pitman, R. M. and Beahm, B. R. and Gundrum, P. G. and Liu, S. Y. and Chen, J. and Paling, J. J. and Dunaway, D. W. and Brooks, W. S. and et al.}, year={2011}, month={Jan}, pages={91–97} } @article{miranda_bland_cambron_lyerly_johnson_buntin_murphy_2010, title={Genetic Mapping of an Aegilops tauschii-derived Hessian Fly Resistance Gene in Common Wheat}, volume={50}, ISSN={["0011-183X"]}, DOI={10.2135/cropsci2009.05.0278}, abstractNote={Hessian fly [Mayetiola destructor (Say)] is a major threat to wheat (Triticum aestivum L.) production in the eastern United States. Cultivar releases containing major Hessian fly resistance genes have proven effective in minimizing losses caused by this pest. Nevertheless, the ephemeral nature of major gene resistance necessitates the identification of novel sources of resistance. Hessian fly resistance from Aegilops tauschii Coss. (2n = 2x = 14; genome DD) was introgressed into the genetic background of the soft red winter wheat cultivar Saluda during the development of the germplasm line NC09MDD14. Our genetic characterization and linkage mapping studies showed that resistance to Hessian Fly biotype L in NC09MDD14 was monogenic and the most likely order of the linked microsatellite markers was: Xcfd13‐ 4.2 cM‐ Xcfd42‐ 1.8 cM‐ Xgdm141‐ 4.9 cM‐ Xgdm36‐ 1.5 cM‐ NC09MDD14 Hf gene/Xcfd132‐ 13.4 cM‐ Xcfd19 This linkage map situated the NCD09MDD14 Hf gene on the short arm of chromosome 6D, within the same deletion bin as the named gene H13 No recombinants between H13 and the NCD09MDD14 Hf gene were found in an allelism study that included 170 F2 individuals from the cross between NCD09MDD14 and Molly (H13). The Hessian fly resistance gene present in the germplasm line NC09MDD14 could be an allele of H13, but unlike H13, the gene in NC09MDD14 provides resistance against biotype vrH13}, number={2}, journal={CROP SCIENCE}, author={Miranda, L. M. and Bland, D. E. and Cambron, S. E. and Lyerly, J. H. and Johnson, J. and Buntin, G. D. and Murphy, J. P.}, year={2010}, pages={612–616} } @article{maxwell_lyerly_srnic_parks_cowger_marshall_brown-guedira_murphy_2010, title={MlAB10: A triticum turgidum subsp dicoccoides derived powdery mildew resistance gene identified in common wheat}, volume={50}, number={6}, journal={Crop Science}, author={Maxwell, J. J. and Lyerly, J. H. and Srnic, G. and Parks, R. and Cowger, C. and Marshall, D. and Brown-Guedira, G. and Murphy, J. P.}, year={2010}, pages={2261–2267} } @article{costa_bockelman_brown-guedira_cambron_chen_cooper_cowger_dong_grybauskas_jin_et al._2010, title={Registration of the Soft Red Winter Wheat Germplasm MD01W233-06-1 Resistant to Fusarium Head Blight}, volume={4}, ISSN={["1936-5209"]}, DOI={10.3198/jpr2010.01.0034crg}, abstractNote={Fusarium head blight (FHB) [caused by Fusarium graminearum Schwabe; telomorph Gibberella zeae (Schwein.) Petch] is a major disease of winter wheat (Triticum aestivum L.) in the US mid‐Atlantic region. The objective of this research was to derive soft red winter wheat (SRWW) germplasm with enhanced FHB resistance for this region. MD01W233–06–1 (Reg. No. GP‐857, PI No. 658682) is a soft red winter wheat (SRWW) (Triticum aestivum L.) germplasm line developed at the University of Maryland and released by the Maryland Agricultural Experiment Station in 2009. MD01W233–06–1 was selected from the cross ‘McCormick’/‘Choptank’ made in 2001. McCormick and Choptank are SRWW cultivars adapted to the US mid‐Atlantic region. MD01W233–06–1 was selected as an F3:5 line selection in Queenstown, MD in June 2006. MD01W233–06–1 has type II resistance to FHB that is different from that of ‘Sumai 3’. Additionally, it has resistance to the Ug99 race of stem rust. These characteristics make this line a valuable contribution for breeding for enhanced FHB resistance in the US mid‐Atlantic.}, number={3}, journal={JOURNAL OF PLANT REGISTRATIONS}, author={Costa, Jose M. and Bockelman, Harold E. and Brown-Guedira, Gina and Cambron, Sue E. and Chen, Xianming and Cooper, Aaron and Cowger, Christina and Dong, Yanghong and Grybauskas, Arvydas and Jin, Yue and et al.}, year={2010}, month={Sep}, pages={255–260} } @inproceedings{advances in breeding for winter hardiness in oats_2009, booktitle={Proceedings of the Annual Meeting, American Society of Agronomy}, year={2009} } @article{maxwell_lyerly_cowger_marshall_brown-guedira_murphy_2009, title={MlAG12: a Triticum timopheevii-derived powdery mildew resistance gene in common wheat on chromosome 7AL}, volume={119}, ISSN={["1432-2242"]}, DOI={10.1007/s00122-009-1150-y}, abstractNote={Wheat powdery mildew is an economically important disease in cool and humid environments. Powdery mildew causes yield losses as high as 48% through a reduction in tiller survival, kernels per head, and kernel size. Race-specific host resistance is the most consistent, environmentally friendly and, economical method of control. The wheat (Triticum aestivum L.) germplasm line NC06BGTAG12 possesses genetic resistance to powdery mildew introgressed from the AAGG tetraploid genome Triticum timopheevii subsp. armeniacum. Phenotypic evaluation of F(3) families derived from the cross NC06BGTAG12/'Jagger' and phenotypic evaluation of an F(2) population from the cross NC06BGTAG12/'Saluda' indicated that resistance to the 'Yuma' isolate of powdery mildew was controlled by a single dominant gene in NC06BGTAG12. Bulk segregant analysis (BSA) revealed simple sequence repeat (SSR) markers specific for chromosome 7AL segregating with the resistance gene. The SSR markers Xwmc273 and Xwmc346 mapped 8.3 cM distal and 6.6 cM proximal, respectively, in NC06BGTAG12/Jagger. The multiallelic Pm1 locus maps to this region of chromosome 7AL. No susceptible phenotypes were observed in an evaluation of 967 F(2) individuals in the cross NC06BGTAG12/'Axminster' (Pm1a) which indicated that the NC06BGTAG12 resistance gene was allelic or in close linkage with the Pm1 locus. A detached leaf test with ten differential powdery mildew isolates indicated the resistance in NC06BGTAG12 was different from all designated alleles at the Pm1 locus. Further linkage and allelism tests with five other temporarily designated genes in this very complex region will be required before giving a permanent designation to this gene. At this time the gene is given the temporary gene designation MlAG12.}, number={8}, journal={THEORETICAL AND APPLIED GENETICS}, author={Maxwell, Judd J. and Lyerly, Jeanette H. and Cowger, Christina and Marshall, David and Brown-Guedira, Gina and Murphy, J. Paul}, year={2009}, month={Nov}, pages={1489–1495} } @article{parks_carbone_murphy_cowger_2009, title={Population Genetic Analysis of an Eastern US Wheat Powdery Mildew Population Reveals Geographic Subdivision and Recent Common Ancestry with UK and Israeli Populations}, volume={99}, ISSN={["1943-7684"]}, DOI={10.1094/PHYTO-99-7-0840}, abstractNote={ The structure of the U.S. wheat powdery mildew population (Blumeria graminis f. sp. tritici) has not been previously investigated, and the global evolutionary history of B. graminis f. sp. tritici is largely unknown. After gathering 141 single-ascosporic B. graminis f. sp. tritici isolates from 10 eastern U.S. locations, 34 isolates from the United Kingdom, and 28 isolates from Israel, we analyzed pathogen population structure using presumptively neutral markers. DNA was extracted from conidia, primers for 12 “housekeeping” genes were designed, and amplicons were examined for polymorphism. Four genes were found to contain a total of 12 single-nucleotide polymorphisms in the U.S. population and were also analyzed in the U.K. and Israeli populations. In total, 25 haplotypes were inferred from the four concatenated genes, with 2 haplotypes comprising over 70% of the U.S. population. Using Hudson's tests and analysis of molecular variance, we found the wheat mildew isolates subdivided into four groups corresponding to distinct regions: the mid-Atlantic United States, the southern United States, the United Kingdom, and Israel. Genotypic diversity was greatest in samples from the United Kingdom, Israel, Virginia, and Kinston, NC. Using rarefaction, a procedure that compensates for differing sample sizes when estimating population richness and diversity, we found that cooler locations with greater conduciveness to regular powdery mildew epidemics had the greatest haplotype richness. Our results suggest that the eastern U.S. B. graminis f. sp. tritici population is young, descended recently from Old World populations with isolation and genetic drift, and is currently subdivided into northern and southern subpopulations. }, number={7}, journal={PHYTOPATHOLOGY}, author={Parks, Ryan and Carbone, Ignazio and Murphy, J. Paul and Cowger, Christina}, year={2009}, month={Jul}, pages={840–849} } @inproceedings{murphy_maxwell_miranda_lyerly_parks_srnic_perugini_cowger_marshall_van esbroeck_et al._2009, title={Qualitative powdery mildew mapping update}, booktitle={Eastern Wheat Workers/Southern Small Grain Workers NCERA184 Conference}, publisher={Baltimore, Md.: Eastern Wheat Workers/Southern Small Grain Workers}, author={Murphy, J. P. and Maxwell, J. J. and Miranda, L. M. and Lyerly, J. H. and Parks, W. R. and Srnic, G. and Perugini, L. and Cowger, C. and Marshall, D. and Van Esbroeck, G. and et al.}, year={2009}, pages={28–30} } @article{wooten_livingston_lyerly_holland_jellen_marshall_murphy_2009, title={Quantitative Trait Loci and Epistasis for Oat Winter-Hardiness Component Traits}, volume={49}, ISSN={["1435-0653"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-70749094348&partnerID=MN8TOARS}, DOI={10.2135/cropsci2008.10.0612}, abstractNote={ABSTRACTWinter hardiness is a complex trait and poor winter hardiness limits commercial production of winter oat (Avena spp.). The objective of this study was to identify quantitative trait loci (QTL) for five winter‐hardiness component traits in a recombinant inbred line population derived from a cross between the winter‐tender cultivar Fulghum and the winter‐hardy cultivar Norline. Crown freezing tolerance, vernalization response, and photoperiod response were evaluated in controlled environment studies. Heading date and plant height were evaluated over two seasons in Kinston, NC, and winter field survival was evaluated in five environments over two seasons in the mountains of North Carolina and Virginia. A partial genetic linkage map of regions believed to affect winter hardiness was developed using restriction fragment length polymorphism and simple sequence repeat markers. Most QTL were located on linkage groups FN3, FN22, and FN24. Quantitative trait loci were identified for all traits except photoperiod response, and epistatic interactions were identified for winter field survival, crown freezing tolerance, vernalization response, and plant height. Major QTL for winter field survival (R 2 = 35%) and crown freezing tolerance (R 2 = 53%) were identified on linkage group FN3, which was associated with an intergenomic reciprocal translocation between chromosomes 7C and 17.}, number={6}, journal={CROP SCIENCE}, author={Wooten, D. R. and Livingston, D. P., III and Lyerly, H. J. and Holland, J. B. and Jellen, E. N. and Marshall, D. S. and Murphy, J. P.}, year={2009}, pages={1989–1998} } @inproceedings{additional markers added to the fulghum/norline genetic map and qtl scan for winter hardiness traits in avena sativa_2008, booktitle={Proceedings, 8th International Oat Conference, Minneapolis, Minn.}, year={2008} } @article{brown-guedira_griffey_kolb_mckendry_murphy_van sanford_2008, title={Breeding Fhb-resistant soft winter wheat: Progress and prospects}, volume={36}, ISSN={["1788-9170"]}, DOI={10.1556/crc.36.2008.suppl.b.5}, abstractNote={Soft winter wheat ( Triticum aestivum L.) breeding programs in the US have used two general approaches to developing FHB-resistant cultivars: 1) incorporation of Fhb 1 plus other minor QTL from Asian wheat cultivars and their derivatives and 2) reliance on resistance native to the soft winter wheat gene pool. Although each approach has shown some success, it is believed that the two must be integrated to develop the highest levels of resistance. The most favorable scenario for integration is the incorporation of Fhb 1 into adapted material with good native resistance, high yield and test weight, and superior milling and baking quality.}, journal={CEREAL RESEARCH COMMUNICATIONS}, author={Brown-Guedira, Gina and Griffey, Carl and Kolb, Fred and Mckendry, Anne and Murphy, J. Paul and Van Sanford, David}, year={2008}, pages={31–35} } @article{wooten_livingston_holland_marshall_murphy_2008, title={Quantitative trait loci and epistasis for crown freezing tolerance in the 'Kanota' x 'Ogle' hexaploid oat mapping population}, volume={48}, ISSN={["1435-0653"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-35348818142&partnerID=MN8TOARS}, DOI={10.2135/cropsci2006.12.0793}, abstractNote={Crown freezing tolerance is the most important factor conferring oat (Avena spp.) winter hardiness. The objective of this study was to identify quantitative trait loci (QTL) for crown freezing tolerance in the ‘Kanota’ × ‘Ogle’ recombinant inbred line (RIL) mapping population and to examine their relationship with other winter hardiness traits. One hundred thirty‐five RILs were evaluated for crown freezing tolerance in a controlled environment. Previously published molecular marker and linkage map information was used for QTL detection. Seven QTL and four complementary epistatic interactions were identified that accounted for 56% of the phenotypic variation. Ogle contributed alleles for increased crown freezing tolerance at three loci, while Kanota contributed alleles for increased crown freezing tolerance at four loci. All loci where Kanota alleles increased crown freezing tolerance showed complementary epistasis for decreased crown freezing tolerance with the QTL near UMN13. Two of the major QTL identified were in the linkage groups (LG) associated with a reciprocal translocation between chromosomes 7C and 17, which was previously associated with spring growth habit in oat. The results confirm the importance of the chromosomes involved in the reciprocal 7C‐17 translocation in controlling winter hardiness component traits.}, number={1}, journal={CROP SCIENCE}, author={Wooten, David R. and Livingston, David P., III and Holland, James B. and Marshall, David S. and Murphy, J. Paul}, year={2008}, pages={149–157} } @article{parks_carbone_murphy_marshall_cowger_2008, title={Virulence structure of the Eastern US wheat powdery mildew population}, volume={92}, ISSN={["0191-2917"]}, DOI={10.1094/PDIS-92-7-1074}, abstractNote={ Little is known about the population structure of wheat powdery mildew in the eastern United States, and the most recent report on virulence in this population involved isolates collected in 1993–94. In the present study, wheat leaves naturally infected with powdery mildew were collected from 10 locations in the southeastern United States in 2003 and 2005 and a collection of 207 isolates was derived from single ascospores. Frequencies of virulence to 16 mildew resistance (Pm) genes were determined by inoculating the isolates individually on replicated plates of detached leaves of differential wheat lines. These virulence frequencies were used to infer local effectiveness of Pm genes, estimate virulence complexity, detect significant associations between pairs of pathogen avirulence loci, and assess whether phenotypic differences between pathogen subpopulations increased with geographic distance. In both years, virulence to Pm3a, Pm3c, Pm5a, and Pm7 was present in more than 90% of sampled isolates and virulence to Pm1a, Pm16, Pm17, and Pm25 was present in fewer than 10% of isolates. In each year, 71 to 88% of all sampled isolates possessed one of a few multilocus virulence phenotypes, although there were significant differences among locations in frequencies of virulence to individual Pm genes. Several significant associations were detected between alleles for avirulence to pairs of Pm genes. Genetic (phenotypic) distance between isolate subpopulations increased significantly (R2 = 0.40, P < 0.001) with increasing geographic separation; possible explanations include different commercial deployment of Pm genes and restricted gene flow in the pathogen population. }, number={7}, journal={PLANT DISEASE}, author={Parks, Ryan and Carbone, Ignazio and Murphy, J. Paul and Marshall, David and Cowger, Christina}, year={2008}, month={Jul}, pages={1074–1082} } @article{wooten_livingston_jellen_boren_marshall_murphy_2007, title={An intergenomic reciprocal translocation associated with oat winter hardiness component traits}, volume={47}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2006.12.0768}, abstractNote={The reciprocal intergenomic translocation between hexaploid oat (Avena sp.) chromosomes 7C and 17 (T7C‐17) has been associated with the division of cultivated oat into A. sativa L. and A. byzantina K. Koch species and differences in crown freezing tolerance and winter field survival. The objectives of this experiment were: (i) to validate the association of T7C‐17 with crown freezing tolerance and winter field survival in a population derived from a cross of the non‐winter‐hardy ‘Fulghum’ (non‐T7C‐17) with winter‐hardy ‘Norline’ (T7C‐17); (ii) to determine if preferential selection for T7C‐17 occurred during inbreeding; and (iii) to examine the association of T7C‐17 with the winter hardiness component traits heading date, plant height, and vernalization and photoperiod responses. Crown freezing tolerance and vernalization and photoperiod responses were evaluated in controlled environment studies. Heading date, plant height, and winter field survival were evaluated in field experiments during two seasons. The presence of the translocation was associated with greater crown freezing tolerance, winter field survival, and days to flowering. Translocation status was not associated with vernalization and photoperiod responses or plant height. The T7C‐17/non‐T7C‐17 segregation ratio was 2:1. These results confirmed the importance of T7C‐17 in conferring winter hardiness traits in winter oat and preferential selection for the translocation during inbreeding.}, number={5}, journal={CROP SCIENCE}, author={Wooten, David R. and Livingston, David P., III and Jellen, Eric N. and Boren, Kathryn J. and Marshall, David S. and Murphy, J. Paul}, year={2007}, pages={1832–1840} } @article{cowger_murphy_2007, title={Artificial inoculation of wheat for selecting resistance to Stagonospora nodorum blotch}, volume={91}, ISSN={["1943-7692"]}, DOI={10.1094/PDIS-91-5-0539}, abstractNote={ In the eastern United States, natural epidemics of Stagonospora nodorum blotch (SNB) are not consistently severe enough to facilitate substantial progress in breeding moderately resistant cultivars of soft red winter wheat. We compared three artificial inoculation methods to natural inoculum in a field experiment involving seven wheat (Triticum aestivum) cultivars with varying levels of SNB resistance. Artificial inoculation methods were: Phaeosphaeria nodorum conidia applied by atomization to three- to four-leaf wheat in early winter, P. nodorum conidia applied by atomization at boot stage in late spring, and P. nodorum-infected wheat straw applied in early winter. The experiment was conducted at Kinston and Plymouth, NC, in 2003–2004, 2004–2005, and 2005–2006, and all treatments had three replicates. Percent diseased canopy was assessed and comparisons were made using disease severity at a single date (early to soft dough stage) and area under the disease progress curve (AUDPC). The relative resistance level of cultivars was consistent across sites, years, and inoculum methods, although the rankings of moderately susceptible and susceptible cultivars were sometimes switched. On average, late spores and straw caused significantly more disease than early spores or natural inoculum (P ≤ 0.05). Biplot analysis indicated that all artificial methods had a higher mean capacity to discriminate among cultivars than did natural inoculum (P ≤ 0.05). On average, artificial inoculation increased the capacity of environments to separate wheat cultivars by SNB resistance. }, number={5}, journal={PLANT DISEASE}, author={Cowger, Christina and Murphy, J. Paul}, year={2007}, month={May}, pages={539–545} } @article{miranda_murphy_marshall_cowger_leath_2007, title={Chromosomal location of Pm35, a novel Aegilops tauschii derived powdery mildew resistance gene introgressed into common wheat (Triticum aestivum L.)}, volume={114}, ISSN={0040-5752 1432-2242}, url={http://dx.doi.org/10.1007/s00122-007-0530-4}, DOI={10.1007/s00122-007-0530-4}, abstractNote={A single gene controlling powdery mildew resistance was identified in the North Carolina germplasm line NC96BGTD3 (NCD3) using genetic analysis of F(2) derived lines from a NCD3 X Saluda cross. Microsatellite markers linked to this Pm gene were identified and their most likely order was Xcfd7, 10.3 cM, Xgdm43, 8.6 cM, Xcfd26, 11.9 cM, Pm gene. These markers and the Pm gene were assigned to chromosome 5DL by means of Chinese Spring Nullitetrasomic (Nulli5D-tetra5A) and ditelosomic (Dt5DL) lines. A detached leaf test showed a distinctive disease reaction to six pathogen isolates among the NCD3 Pm gene, Pm2 (5DS) and Pm34 (5DL). An allelism test showed independence between Pm34 and the NCD3 Pm gene. Together, the tests provided strong evidence for the presence of a novel Pm gene in NCD3, and this gene was designated Pm35.}, number={8}, journal={Theoretical and Applied Genetics}, publisher={Springer Science and Business Media LLC}, author={Miranda, L. M. and Murphy, J. P. and Marshall, D. and Cowger, C. and Leath, S.}, year={2007}, month={Mar}, pages={1451–1456} } @article{miranda_perugini_srnic_brown-guedira_marshall_leath_murphy_2007, title={Genetic mapping of a Triticum monococcum-derived powdery mildew resistance gene in common wheat}, volume={47}, ISSN={["0011-183X"]}, DOI={10.2135/cropsci2007.01.0053}, abstractNote={Powdery mildew of wheat (Triticum aestivum L.) is a major fungal disease caused by Blumeria graminis DC f. sp. tritici A microsatellite linkage map was developed for the T. monococcum‐derived powdery mildew resistant gene present in the North Carolina germplasm line NCBGT96A6 (NCA6). Genetic analysis of F2‐derived lines from the cross NCA6 × ‘Saluda’ indicated a single gene controlled powdery mildew resistance. Four microsatellite markers linked to the NCA6 Pm gene mapped to chromosome 7AL. The most likely order was Xcfa2123‐0.9 cM–Xbarc121‐1.7 cM resistance gene/Xcfa2019‐3.0 cM‐Xgwm332 A detached‐leaf test indicated the disease reaction response of the NCA6 Pm gene was different from the five known alleles at the Pm1 locus on 7AL. Deletion interval mapping showed a large physical to genetic distance ratio for these microsatellite marker loci. This may be due to suppressed recombination between the introgressed T. monococcum segment and the homologous region of the T. aestivum cultivar Saluda. Our results suggested that the NCA6 Pm gene is likely a novel source of resistance to powdery mildew but additional allelism studies are needed to establish the relationship between this locus and the other known Pm loci on 7AL.}, number={6}, journal={CROP SCIENCE}, author={Miranda, L. M. and Perugini, L. and Srnic, G. and Brown-Guedira, G. and Marshall, D. and Leath, S. and Murphy, J. P.}, year={2007}, pages={2323–2329} } @inproceedings{miranda_maxwell_perugini_srnic_shi_lyerly_navarro_cowger_marshall_brown-guedira_et al._2007, title={Genetics and mapping of powdery mildew resistance in North Carolina wheat germplasms}, booktitle={Proceedings of the Annual Meeting, American Society of Agronomy}, author={Miranda, L. and Maxwell, J. and Perugini, L. and Srnic, G. and Shi, A. and Lyerly, J. and Navarro, R. and Cowger, C. and Marshall, D. and Brown-Guedira, G. and et al.}, year={2007} } @article{perugini_murphy_marshall_brown-guedira_2008, title={Pm37, a new broadly effective powdery mildew resistance gene from Triticum timopheevii}, volume={116}, ISSN={["1432-2242"]}, DOI={10.1007/s00122-007-0679-x}, abstractNote={Powdery mildew is an important foliar disease in wheat, especially in areas with a cool or maritime climate. A dominant powdery mildew resistance gene transferred to the hexaploid germplasm line NC99BGTAG11 from T. timopheevii subsp. armeniacum was mapped distally on the long arm of chromosome 7A. Differential reactions were observed between the resistance gene in NC99BGTAG11 and the alleles of the Pm1 locus that is also located on chromosome arm 7AL. Observed segregation in F2:3 lines from the cross NC99BGTAG11xAxminster (Pm1a) demonstrate that germplasm line NC99BGTAG11 carries a novel powdery mildew resistance gene, which is now designated as Pm37. This new gene is highly effective against all powdery mildew isolates tested so far. Analyses of the population with molecular markers indicate that Pm37 is located 16 cM proximal to the Pm1 complex. Simple sequence repeat (SSR) markers Xgwm332 and Xwmc790 were located 0.5 cM proximal and distal, respectively, to Pm37. In order to identify new markers in the region, wheat expressed sequence tags (ESTs) located in the distal 10% of 7AL that were orthologous to sequences from chromosome 6 of rice were targeted. The two new EST-derived STS markers were located distal to Pm37 and one marker was closely linked to the Pm1a region. These new markers can be used in marker-assisted selection schemes to develop wheat cultivars with pyramids of powdery mildew resistance genes, including combinations of Pm37 in coupling linkage with alleles of the Pm1 locus.}, number={3}, journal={THEORETICAL AND APPLIED GENETICS}, author={Perugini, L. D. and Murphy, J. P. and Marshall, D. and Brown-Guedira, G.}, year={2008}, month={Feb}, pages={417–425} } @inproceedings{maxwell_cowger_marshall_kolmer_brown-guedira_lyerly_murphy_2007, title={Powdery mildew and leaf rust resistance in winter wheat germplasm lines}, booktitle={ASA-CSSA-SSSA International Annual Meetings, New Orleans, LA}, author={Maxwell, J. and Cowger, C. and Marshall, D. and Kolmer, J. and Brown-Guedira, G. and Lyerly, J. and Murphy, P.}, year={2007} } @inproceedings{murphy_navarro_lyerly_2006, title={2005-06 uniform Southern fusarium head blight screening nursery}, booktitle={Proceedings of the 2006 National Fusarium Head Blight Forum, 2006 Dec. 10-12, Research Triangle Park, NC}, author={Murphy, J. P. and Navarro, R. A. and Lyerly, J. H.}, year={2006}, pages={114} } @article{santos_livingston_jellen_wooten_murphy_2006, title={A cytological marker associated with winterhardiness in oat}, volume={46}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2005.0152}, abstractNote={The intergenomic translocation T7C‐17 occurs at different frequencies in fall‐ versus spring‐sown hexaploid oat (Avena sp.) germplasm. The objectives of this experiment were to evaluate crown meristem freeze tolerance and winter field survival among 94 random F4–derived lines from the cross between the cultivars Wintok (T7C‐17, winterhardy) and Fulghum (non‐T7C‐17, less winterhardy) and to examine the association between these winterhardiness traits and T7C‐17. Crown meristem freeze tolerance was evaluated in a three‐replicate randomized complete block design in controlled environment growth cabinets. Field survival was evaluated in a three replicate randomized complete block design at Laurel Springs, NC during the 1999–2000 season. Greater crown meristem freeze tolerance and greater winter field survival were associated with the presence of T7C‐17. Lines heterogeneous for the translocation had similar levels of crown meristem freeze tolerance and field survival as lines homozygous for the translocation. Twenty‐two percent of the variation in crown meristem freeze tolerance and 27% of the variation in field survival was accounted for by translocation status. The observed frequencies of translocation homozygotes and heterozygotes did not fit the expected frequencies for single factor segregation in the F4 generation. There were almost threefold as many homozygotes with the translocation as homozygotes without the translocation which indicated preferential selection for T7C‐17 during inbreeding. Our results suggested that T7C‐17 might be isolating, in terms of recombination, either a dominant allele or a group of loci conditioning winterhardiness in our population.}, number={1}, journal={CROP SCIENCE}, author={Santos, AG and Livingston, DR and Jellen, EN and Wooten, DR and Murphy, JP}, year={2006}, pages={203–208} } @article{farrer_weisz_heiniger_murphy_pate_2006, title={Delayed harvest effect on soft red winter wheat in the southeastern USA}, volume={98}, ISSN={["1435-0645"]}, DOI={10.2134/agronj2005.0211}, abstractNote={Harvest of soft red winter wheat (Triticum aestivum L.) in the southeastern USA can be delayed because of inclement weather or other unforeseen problems. Our objectives were to determine the impact of delaying harvest beyond grain ripeness (135 g kg−1 grain moisture content) on yield, test weight, grain protein, and 20 milling and baking quality parameters, and to determine if these impacts were correlated with environmental conditions occurring between grain ripeness and harvest. In 2001 and 2002, a total of six trials were conducted where treatments consisted of a timely harvest at grain ripeness and a delayed harvest, 8 to 19 d later. Yield was reduced by up to ∼900 kg ha−1 due to delayed harvest, with yield losses negatively related to total precipitation and positively related to minimum daily temperatures (R2 = 0.99) during the delay interval, indicating that dry and warm environments increased yield losses. Test weight reductions up to ∼115 kg m−3 were seen and were linearly related to the number of precipitation events (r2 = 0.93) between harvests. Grain protein was not affected by delayed harvest. Of the milling and baking quality parameters measured, grain and flour falling number, clear flour percentage, grain deoxynivalenol (DON), and farinograph breakdown times were negatively affected by delayed harvest. Lower falling numbers and higher levels of DON are consistent with the high humidity and rainfall typical of the southeastern USA wheat harvest and are problematic for millers. Decreased farinograph breakdown times can be a problem for bakers.}, number={3}, journal={AGRONOMY JOURNAL}, author={Farrer, Dianne and Weisz, Randy and Heiniger, Ronnie and Murphy, J. Paul and Pate, Michael H.}, year={2006}, pages={588–595} } @article{jia_livingston_murphy_porter_2006, title={Evaluation of freezing tolerance in advanced progeny from a cross of Avena sativa X A-macrostachya}, volume={34}, ISSN={["1788-9170"]}, DOI={10.1556/CRC.34.2006.2-3.235}, abstractNote={Avena macrostachya is a perennial, autotetraploid oat. In its natural habitat it has a high degree of winter hardiness. The objective of this experiment was to screen 53 backcross progenies of an interspecific cross between the cultivar Brooks ( A. sativa ) and A. macrostachya using a controlled freezing test. No entry tested was more freezing tolerant than the recurrent parent Brooks. These results indicated that freeze tolerance from A. macrostachya had not been introgressed into the progeny. It was suggested that the mechanism for winter hardiness in A. macrostachya is different from that in A. sativa and may involve an escape mechanism rather than a genetically controlled freezing resistance mechanism.}, number={2-3}, journal={CEREAL RESEARCH COMMUNICATIONS}, author={Jia, Hongmei and Livingston, David P., III and Murphy, J. Paul and Porter, David R.}, year={2006}, pages={1037–1042} } @article{farrer_weisz_heiniger_murphy_white_2006, title={Minimizing protein variability in soft red winter wheat: Impact of nitrogen application timing and rate}, volume={98}, ISSN={["0002-1962"]}, DOI={10.2134/agronj2006.0039}, abstractNote={Grain protein content in soft red winter wheat (Triticum aestivum L.) is highly variable across years and environments in the southeastern USA. This variability makes southeastern wheat undesirable to millers and negatively impacts its value in the export market. The objectives of this study were to determine how different N fertilizer rates and application times would affect grain protein variability and to determine if there were N fertilizer recommendations that would minimize regional protein variation. We conducted experiments in the North Carolina Piedmont, Coastal Plain, and Tidewater in 2001 and 2002. At each site–year, we used a split‐plot design with three or five N fertilizer rates at growth‐stage 25 (GS) (main plots), and an additional five N fertilizer rates applied at GS 30 (subplots). Analysis of variance indicated that environment contributed 68 and 90.5% of the variability in yield and test weight, respectively. Though environment contributed 23.3% of grain protein variability, the majority (51.4%) was attributed to timing and rate of N application. As grain protein levels increased at higher N rates, so did overall protein variability. Additionally, applying the majority of N fertilizer at GS 30 increased grain protein variability compared to application at GS 25. Based on these results, our recommendations to reduce grain protein variability in the southeastern USA are to: (i) reduce the range in N fertilizer rates used across the region, (ii) avoid overapplication of N beyond what is required to optimize yield and economic return, and (iii) apply spring N at GS 25.}, number={4}, journal={AGRONOMY JOURNAL}, publisher={American Society of Agronomy}, author={Farrer, Dianne C. and Weisz, Randy and Heiniger, Ronnie and Murphy, J. Paul and White, Jeffrey G.}, year={2006}, pages={1137–1145} } @article{miranda_murphy_marshall_leath_2006, title={Pm34: a new powdery mildew resistance gene transferred from Aegilops tauschii Coss. to common wheat (Triticum aestivum L.)}, volume={113}, ISSN={["1432-2242"]}, DOI={10.1007/s00122-006-0397-9}, abstractNote={Powdery mildew is a major fungal disease in wheat growing areas worldwide. A novel source of resistance to wheat powdery mildew present in the germplasm line NC97BGTD7 was genetically characterized as a monogenic trait in greenhouse and field trials using F(2) derived lines from a NC97BGTD7 X Saluda cross. Microsatellite markers were used to map and tag this resistance gene, now designated Pm34. Three co-dominant microsatellite markers linked to Pm34 were identified and their most likely order was established as: Xbarc177-5D, 5.4cM, Pm34, 2.6cM, Xbarc144-5D, 14cM, Xgwm272-5D. These microsatellite markers were previously mapped to the long arm of the 5D chromosome and their positions were confirmed using Chinese Spring nullitetrasomic Nulli5D-tetra5A and ditelosomic Dt5DL lines. Pm2, the only other known Pm gene on chromosome 5D, has been mapped to the short arm and its specificity is different from that of Pm34.}, number={8}, journal={THEORETICAL AND APPLIED GENETICS}, author={Miranda, L. M. and Murphy, J. P. and Marshall, D. and Leath, S.}, year={2006}, month={Nov}, pages={1497–1504} } @inproceedings{wooten_livingston_lyerly_murphy_2006, title={Quantitative trait loci for winter hardiness component traits in oat}, booktitle={2006 American Oat Workers Conference, Program book}, publisher={Fargo, ND: American Oat Workers Conference}, author={Wooten, D. R. and Livingston, D. P. and Lyerly, J. H. and Murphy, J. P.}, year={2006}, pages={63} } @inproceedings{wooten_livingston_lyerly_murphy_2006, title={Quantitative trait loci for winter hardiness in oat}, booktitle={ASA-CSSA-SSSA International Annual Meetings, November 12-16, 2006, Indianapolis, IN}, author={Wooten, D. R. and Livingston, D. P. and Lyerly, J. H. and Murphy, J. P.}, year={2006} } @article{subudhi_parami_harrison_materne_murphy_nash_2005, title={An AFLP-based survey of genetic diversity among accessions of sea oats (Uniola paniculata, Poaceae) from the southeastern Atlantic and Gulf coast states of the United States}, volume={111}, ISSN={["0040-5752"]}, DOI={10.1007/s00122-005-0096-y}, abstractNote={Uniola paniculata, commonly known as sea oats, is a C4 perennial grass capable of stabilizing sand dunes. It is most abundant along the Gulf of Mexico and southeastern Atlantic coastal regions of the United States. The species exhibits low seed set and low rates of germination and seedling emergence, and so extensive clonal reproduction is achieved through production of rhizomes, which may contribute to a decline in genetic diversity. To date, there has been no systematic assessment of genetic variability and population structure in naturally occurring stands in the USA. This study was conducted to assess the genetic relationship and diversity among nineteen U. paniculata accessions representing eight states: Texas, Louisiana, Mississippi, Alabama, Florida, South Carolina, North Carolina, and Virginia, using amplified fragment length polymorphism (AFLP). Twelve AFLP EcoRI + MseI primer combinations generated a wide range of polymorphisms (42-81%) with a mean of 59%. Overall, the sea oats plants exhibited a low range of genetic similarity. Florida accessions, FL-33 and FL-39, were most genetically diverse and the accessions from both Carolinas and Virginia (NC-1, NC-11, SC-15, and VA-53) harbored less genetic variability. Cluster analysis using the UPGMA approach separated U. paniculata plants into four major clusters which were also confirmed by principal coordinate analysis (PCO). Further examination of the different components of genetic variation by analysis of molecular variance (AMOVA) indicated the largest proportion of variability at the state level (47.8%) followed by the variation due to the differences among the genotypes within an accession (34.4%), and the differences among the accessions within a state (17.8%). The relationship between genetic diversity and geographic source of sea oats populations of the United States as revealed through this comprehensive study will be helpful to resource managers and commercial nurseries in identifying suitable plant materials for restoration of new areas without compromising the adaptation and genetic diversity.}, number={8}, journal={THEORETICAL AND APPLIED GENETICS}, author={Subudhi, PK and Parami, NP and Harrison, SA and Materne, MD and Murphy, JP and Nash, D}, year={2005}, month={Nov}, pages={1632–1641} } @article{reberg-horton_burton_danehower_ma_monks_murphy_ranells_williamson_creamer_2005, title={Changes over time in the allelochemical content of ten cultivars of rye (Secale cereale L.)}, volume={31}, ISSN={["1573-1561"]}, DOI={10.1007/s10886-005-0983-3}, abstractNote={Published studies focused on characterizing the allelopathy-based weed suppression by rye cover crop mulch have provided varying and inconsistent estimates of weed suppression. Studies were initiated to examine several factors that could influence the weed suppressiveness of rye: kill date, cultivar, and soil fertility. Ten cultivars of rye were planted with four rates of nitrogen fertilization, and tissue from each of these treatment combinations was harvested three times during the growing season. Concentrations of a known rye allelochemical DIBOA (2,4-dihydroxy-1,4-(2H)benzoxazine-3-one) were quantified from the harvested rye tissue using high performance liquid chromatography (HPLC). Phytotoxicity observed from aqueous extracts of the harvested rye tissue correlated with the levels of DIBOA recovered in harvested tissue. The amount of DIBOA in rye tissue varied depending on harvest date and rye cultivar, but was generally lower with all cultivars when rye was harvested later in the season. However, the late maturing variety 'Wheeler' retained greater concentrations of DIBOA in comparison to other rye cultivars when harvested later in the season. The decline in DIBOA concentrations as rye matures, and the fact that many rye cultivars mature at different rates may help explain why estimates of weed suppression from allelopathic agents in rye have varied so widely in the literature.}, number={1}, journal={JOURNAL OF CHEMICAL ECOLOGY}, publisher={Springer Nature}, author={Reberg-Horton, SC and Burton, JD and Danehower, DA and Ma, GY and Monks, DW and Murphy, JP and Ranells, NN and Williamson, JD and Creamer, NG}, year={2005}, month={Jan}, pages={179–193} } @article{browne_murphy_cooke_devaney_walsh_griffey_hancock_harrison_hart_kolb_et al._2005, title={Evaluation of components of Fusarium head blight resistance in soft red winter wheat germ plasm using a detached leaf assay}, volume={89}, ISSN={["0191-2917"]}, DOI={10.1094/PD-89-0404}, abstractNote={ A large environmental influence on phenotypic estimates of disease resistance and the complex polygenic nature of Fusarium head blight (FHB) resistance in wheat (Triticum aestivum) are impediments to developing resistant cultivars. The objective of this research was to investigate the utility of a detached leaf assay, inoculated using inoculum from isolates of Microdochium nivale var. majus, to identify components of FHB resistance among 30 entries of U.S. soft red winter wheat in the 2002 Uniform Southern FHB Nursery (USFHBN). Whole plant FHB resistance of the USFHBN entries was evaluated in replicated, mist-irrigated field trials at 10 locations in eight states during the 2001-2002 season. Incubation period (days from inoculation to the first appearance of a dull gray-green water-soaked lesion) was the only detached leaf variable significantly correlated across all FHB resistance parameters accounting for 45% of the variation in FHB incidence, 27% of FHB severity, 30% of Fusarium damaged kernels, and 26% of the variation in grain deoxynivalenol (DON) concentration. The results for incubation period contrasted with previous studies of moderately resistant European cultivars, in that longer incubation period was correlated with greater FHB susceptibility, but agreed with previous findings for the Chinese cultivar Sumai 3 and CIMMYT germ plasm containing diverse sources of FHB resistance. The results support the view that the detached leaf assay method has potential for use to distinguish between specific sources of FHB resistance when combined with data on FHB reaction and pedigree information. For example, entry 28, a di-haploid line from the cross between the moderately resistant U.S. cultivar Roane and the resistant Chinese line W14, exhibited detached leaf parameters that suggested a combination of both sources of FHB resistance. The USFHBN represents the combination of adapted and exotic germ plasm, but four moderately resistant U.S. commercial cultivars (Roane, McCormick, NC-Neuse, and Pat) had long incubation and latent periods and short lesion lengths in the detached leaf assay as observed in moderately FHB resistant European cultivars. The dichotomy in the relationship between incubation period and FHB resistance indicates that this may need to be considered to effectively combine exotic and existing/adapted sources of FHB resistance. }, number={4}, journal={PLANT DISEASE}, author={Browne, RA and Murphy, JP and Cooke, BM and Devaney, D and Walsh, EJ and Griffey, CA and Hancock, JA and Harrison, SA and Hart, P and Kolb, FL and et al.}, year={2005}, month={Apr}, pages={404–411} } @article{weisz_tarleton_murphy_kolb_2005, title={Identifying soft red winter wheat cultivars tolerant to Barley yellow dwarf virus}, volume={89}, ISSN={["1943-7692"]}, DOI={10.1094/PD-89-0170}, abstractNote={ Barley yellow dwarf virus (BYDV) is a serious disease of soft red winter wheat. Although there has been interest in tolerant cultivars, identification and development has been slow due to a lack of precision in rating plants for response to BYDV. Visual ratings of symptoms are commonly used to evaluate cultivars, but these ratings have proven to be inconsistent. The objectives of this research were to assess BYDV visual symptom ratings of wheat cultivars under field conditions, to measure disease-related yield reductions in these cultivars, to determine if a relationship exists between BYDV visual symptoms and yield reductions, and to determine BYDV cultivar tolerance. A split-plot design with insecticide treatment (main plot) and 11 cultivars (subplots) was employed over 4 years. The overall relationship between symptom ratings and BYDV yield reductions was weak (R2 = 0.40) and not consistent across years or cultivars. A consistency of performance analysis showed cultivars clustered into five distinct tolerance classes. Under conditions of high BYDV infestation, visual symptom ratings could be cautiously used to identify highly tolerant cultivars. The most reliable method for rating cultivar tolerance was a direct measure of disease-induced yield reduction across multiple environments. }, number={2}, journal={PLANT DISEASE}, author={Weisz, R and Tarleton, B and Murphy, JP and Kolb, FL}, year={2005}, month={Feb}, pages={170–176} } @article{srnic_murphy_lyerly_leath_marshall_2005, title={Inheritance and chromosomal assignment of powdery mildew resistance genes in two winter wheat germplasm lines}, volume={45}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2004.0530}, abstractNote={Powdery mildew of wheat (Triticum aestivum L.), caused by Blumeria graminis DC f. sp. tritici Em. Marchal, occurs annually in eastern North America resulting in reduced grain yield and end‐use quality in susceptible cultivars. The objectives of this study were to determine the inheritance, chromosomal location, and linkage with molecular markers of powdery mildew resistance genes in the two recently released germplasm lines NC96BGTA4 and NC99BGTAG11. Between 99 and 194 F2:3 progenies plus parents in two populations, ‘Saluda’ × NC96BGTA4 and Saluda × NC99BGTAG11, were evaluated in greenhouse and field nurseries for reaction to powdery mildew infection. Results indicated that the germplasm lines each contained a different, partially dominant, major resistance gene. The two segregating populations were subjected to amplified fragment length polymorphism (AFLP) and simple sequence repeat, or microsatellite (SSR) analyses. Both resistance genes were located on the long arm of chromosome 7A. The most likely locus order indicated that the resistance gene in NC96BGTA4 was flanked by the SSR loci Xbarc292 and Xwmc525 The resistance gene in NC99BGTAG11 was most likely flanked by the AFLP markers XE38M54‐196 and XE36M55‐126, and the SSR loci Xgwm332 and Xwmc525 Both genes mapped to a chromosome arm that contains the powdery mildew resistance loci Pm1 and Pm9 The resistance genes in the two germplasms are different from the Pm1a allele. Our mapping results suggested that the resistance genes were not alleles at the Pm1 or Pm9 loci, but further allelism tests are necessary to determine the relationships both between the two genes themselves and between the two genes and named Pm loci on chromosome 7AL.}, number={4}, journal={CROP SCIENCE}, author={Srnic, G and Murphy, JP and Lyerly, JH and Leath, S and Marshall, DS}, year={2005}, pages={1578–1586} } @inproceedings{murphy_navarro_lyerly_2005, title={The 2004-05 uniform Southern fusarium head blight screening nursery}, booktitle={Proceedings of the 2005 National Fusarium Head Blight Forum, 2005 Dec. 11-13, Milwaukee, WI}, publisher={East Lansing: Michigan State University}, author={Murphy, J. P. and Navarro, R. A. and Lyerly, J. H.}, year={2005}, pages={73} } @article{livingston_elwinger_murphy_2004, title={Moving beyond the winter hardiness plateau in US oat germplasm}, volume={44}, ISSN={["0011-183X"]}, DOI={10.2135/cropsci2004.1966}, abstractNote={Progress has been slow in the development of winter-hardy oat (Avena sativa L.) cultivars. No cultivar released in the last 40 yr has better freezing tolerance than the cultivar Norline, which was released in 1960. However, in an analysis of 65 yr of field testing, Norline was not more winter hardy than 'Wintok', which was released in 1940. An analysis of individual location-year combinations of Wintok and Norline suggested that progeny from a cross of these two cultivars might contain germplasm that was transgressive for freezing tolerance. The objective of this research was to use mass selection in controlled environment freeze tests on successive segregating generations of the cross between Wintok and Norline to identify inbred progenies with significantly greater winter hardiness than either parent. Following three generations of seed increase and three generations of selection for freezing tolerance in controlled freeze tests, several F 7 genotypes were identified with greater freezing tolerance than both parents. In the F 9 generation, two of the lines exhibited a higher level of freezing tolerance than either parent, and both were slightly more freezing tolerant than the moderately winter-hardy barley, Hordeum vulgare 'Trebi'.}, number={6}, journal={CROP SCIENCE}, author={Livingston, DP and Elwinger, GF and Murphy, JP}, year={2004}, pages={1966–1969} } @article{murphy_navarro_leath_bowman_weisz_ambrose_pate_fountain_2004, title={Registration of 'NC-Neuse' wheat}, volume={44}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2004.1479}, abstractNote={Crop ScienceVolume 44, Issue 4 p. 1479-1480 Registration of Cultivar Registration of ‘NC-Neuse’ Wheat J.P. Murphy, Corresponding Author J.P. Murphy njpm@unity.ncsu.edu Dep. of Crop Science, North Carolina State Univ., Raleigh, NC, 27695-7629Corresponding author (njpm@unity.ncsu.edu)Search for more papers by this authorR.A. Navarro, R.A. Navarro Dep. of Crop Science, North Carolina State Univ., Raleigh, NC, 27695-7629Search for more papers by this authorS. Leath, S. Leath Dep. of Plant Pathology, North Carolina State Univ., Raleigh, NC, 27695-7629Search for more papers by this authorD.T. Bowman, D.T. Bowman Dep. of Crop Science, North Carolina State Univ., Raleigh, NC, 27695-7629Search for more papers by this authorP.R. Weisz, P.R. Weisz Dep. of Crop Science, North Carolina State Univ., Raleigh, NC, 27695-7629Search for more papers by this authorL.G. Ambrose, L.G. Ambrose Beaufort Co. CES, 155 Airport Rd., Washington, NC, 27889Search for more papers by this authorM.H. Pate, M.H. Pate MidState Mills, Inc., P.O. Box 350, Newton, NC, 28658Search for more papers by this authorM.O. Fountain, M.O. Fountain Dep. of Crop Science, North Carolina State Univ., Raleigh, NC, 27695-7629Search for more papers by this author J.P. Murphy, Corresponding Author J.P. Murphy njpm@unity.ncsu.edu Dep. of Crop Science, North Carolina State Univ., Raleigh, NC, 27695-7629Corresponding author (njpm@unity.ncsu.edu)Search for more papers by this authorR.A. Navarro, R.A. Navarro Dep. of Crop Science, North Carolina State Univ., Raleigh, NC, 27695-7629Search for more papers by this authorS. Leath, S. Leath Dep. of Plant Pathology, North Carolina State Univ., Raleigh, NC, 27695-7629Search for more papers by this authorD.T. Bowman, D.T. Bowman Dep. of Crop Science, North Carolina State Univ., Raleigh, NC, 27695-7629Search for more papers by this authorP.R. Weisz, P.R. Weisz Dep. of Crop Science, North Carolina State Univ., Raleigh, NC, 27695-7629Search for more papers by this authorL.G. Ambrose, L.G. Ambrose Beaufort Co. CES, 155 Airport Rd., Washington, NC, 27889Search for more papers by this authorM.H. Pate, M.H. Pate MidState Mills, Inc., P.O. Box 350, Newton, NC, 28658Search for more papers by this authorM.O. Fountain, M.O. Fountain Dep. of Crop Science, North Carolina State Univ., Raleigh, NC, 27695-7629Search for more papers by this author First published: 01 July 2004 https://doi.org/10.2135/cropsci2004.1479Citations: 17 Research supported in part by grants from the North Carolina Small Grains Growers Association, the North Carolina Foundation Seed Producers, Inc., and the North Carolina Crop Improvement Association. Registration by CSSA. Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume44, Issue4July–August 2004Pages 1479-1480 RelatedInformation}, number={4}, journal={CROP SCIENCE}, author={Murphy, JP and Navarro, RA and Leath, S and Bowman, DT and Weisz, PR and Ambrose, LG and Pate, MH and Fountain, MO}, year={2004}, pages={1479–1480} } @article{fraser_murphy_leath_van sanford_2003, title={Effect of inoculation with selected isolates of Stagonospora nodorum on field evaluations of host resistance in winter wheat}, volume={87}, ISSN={["1943-7692"]}, DOI={10.1094/PDIS.2003.87.10.1213}, abstractNote={ Although Stagonospora nodorum blotch occurs annually in North Carolina, selection for resistance in wheat (Triticum aestivum) breeding nurseries is hampered by the infrequent occurrence of heavy and timely disease pressure. The objective of this study was to compare estimates of host resistance in a population of 147 random winter wheat lines evaluated in epidemics produced by natural infection versus epidemics supplemented by inoculation with selected isolates. Two isolates were chosen from a set of 43 collected in North Carolina based on their aggressiveness on four wheat cultivars in a controlled environment test. Field experiments utilized a split-plot design with three replications. The main plots were inoculation treatments and the subplots were the 147 wheat genotypes. The inoculation treatments were (i) selected isolate A (more aggressive) alone, (ii) selected isolate B (less aggressive) alone, (iii) a combination of isolates A plus B, and (iv) natural infection. Selected isolate treatments were applied at Feekes growth stage 9 to 10.1, and disease intensity was measured two or three times at 14-day intervals postinoculation. The study was conducted at one location in the 1996-97 season and two locations in the 1997-98 season. High levels of natural infection occurred, and no differences were observed among the four inoculation treatments for mean disease intensity in any of the three environments. Within environments, genotype-by-inoculation treatment variance was significant in the two environments inoculated with selected isolates at growth stage 9 but not in the environment inoculated at growth stage 10.1. Magnitudes of genetic variation and heritability for Stagonospora nodorum blotch resistance were not consistently associated with main plot treatments, and inoculation with selected isolates masked genetic variation for resistance in two treatments in one environment. Genotype rank correlations for Stagonospora nodorum blotch resistance between inoculation treatments varied from zero to 0.69 within environments, but only a single correlation between inoculation treatments in different environments was observed. Estimates of host resistance in epidemics supplemented with selected isolates did not consistently agree with estimates in epidemics produced by natural infection. Our results did not support the routine use of supplemental inoculation of wheat breeding nurseries with selected isolates of S. nodorum as a means of increasing genetic gain for host resistance. }, number={10}, journal={PLANT DISEASE}, author={Fraser, DE and Murphy, JP and Leath, S and Van Sanford, DA}, year={2003}, month={Oct}, pages={1213–1220} } @article{baohong_zhou_murphy_2003, title={Genetic variation within Chinese and western cultivated oat accessions}, volume={31}, number={04-Mar}, journal={Cereal Research Communications}, author={Baohong, G. and Zhou, X. and Murphy, J. P.}, year={2003}, pages={339–346} } @article{murphy_navarro_leath_bowman_2002, title={Registration of 'NC Hulless' oat}, volume={42}, ISSN={["0011-183X"]}, DOI={10.2135/cropsci2002.0311}, abstractNote={Crop ScienceVolume 42, Issue 1 p. 311-311 Registration of Cultivars Registration of ‘NC Hulless’ Oat J.P. Murphy, Corresponding Author J.P. Murphy njpm@unity.ncsu.edu Dep. of Crop Science, North Carolina State Univ., Raleigh, NC, 27695-7629Corresponding author (njpm@unity.ncsu.edu)Search for more papers by this authorR.A. Navarro, R.A. Navarro Dep. of Crop Science, North Carolina State Univ., Raleigh, NC, 27695-7629Search for more papers by this authorS. Leath, S. Leath USDA-ARS, Dep. of Plant Pathology, North Carolina State Univ., Raleigh, NC, 27695-7629Search for more papers by this authorD.T. Bowman, D.T. Bowman Dep. of Crop Science, North Carolina State Univ., Raleigh, NC, 27695-7629Search for more papers by this author J.P. Murphy, Corresponding Author J.P. Murphy njpm@unity.ncsu.edu Dep. of Crop Science, North Carolina State Univ., Raleigh, NC, 27695-7629Corresponding author (njpm@unity.ncsu.edu)Search for more papers by this authorR.A. Navarro, R.A. Navarro Dep. of Crop Science, North Carolina State Univ., Raleigh, NC, 27695-7629Search for more papers by this authorS. Leath, S. Leath USDA-ARS, Dep. of Plant Pathology, North Carolina State Univ., Raleigh, NC, 27695-7629Search for more papers by this authorD.T. Bowman, D.T. Bowman Dep. of Crop Science, North Carolina State Univ., Raleigh, NC, 27695-7629Search for more papers by this author First published: 01 January 2002 https://doi.org/10.2135/cropsci2002.3110 Research supported in part by grants from the North Carolina Small Grains Growers Association, Inc. and the USDA-ARS. Registration by CSSA. Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Volume42, Issue1January–February 2002Pages 311-311 RelatedInformation}, number={1}, journal={CROP SCIENCE}, author={Murphy, JP and Navarro, RA and Leath, S and Bowman, DT}, year={2002}, pages={311–311} } @article{murphy_navarro_leath_2002, title={Registration of NC99BGTAG11 wheat germplasm resistant to powdery mildew}, volume={42}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2002.1382}, abstractNote={Crop ScienceVolume 42, Issue 4 p. 1382-1382 Registration of Germplasm Registration of NC99BGTAG11 Wheat Germplasm Resistant to Powdery Mildew J.P. Murphy, Corresponding Author J.P. Murphy njpm@unity.ncsu.edu Dep. of Crop Science, North Carolina State Univ., Raleigh, NC, 27695-7629Corresponding author (njpm@unity.ncsu.edu)Search for more papers by this authorR.A. Navarro, R.A. Navarro Dep. of Crop Science, North Carolina State Univ., Raleigh, NC, 27695-7629Search for more papers by this authorS. Leath, S. Leath USDA-ARS, Dep. Plant Pathology, North Carolina State Univ., Raleigh, NC, 27695-7629Search for more papers by this author J.P. Murphy, Corresponding Author J.P. Murphy njpm@unity.ncsu.edu Dep. of Crop Science, North Carolina State Univ., Raleigh, NC, 27695-7629Corresponding author (njpm@unity.ncsu.edu)Search for more papers by this authorR.A. Navarro, R.A. Navarro Dep. of Crop Science, North Carolina State Univ., Raleigh, NC, 27695-7629Search for more papers by this authorS. Leath, S. Leath USDA-ARS, Dep. Plant Pathology, North Carolina State Univ., Raleigh, NC, 27695-7629Search for more papers by this author First published: 01 July 2002 https://doi.org/10.2135/cropsci2002.1382Citations: 7 Research supported in part by the North Carolina Small Grains Growers Association, Inc. Registration by CSSA. Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume42, Issue4July–August 2002Pages 1382-1382 RelatedInformation}, number={4}, journal={CROP SCIENCE}, author={Murphy, JP and Navarro, RA and Leath, S}, year={2002}, pages={1382–1382} } @article{walker_leath_hagler_murphy_2001, title={Variation among isolates of Fusarium graminearum associated with Fusarium head blight in North Carolina}, volume={85}, ISSN={["0191-2917"]}, DOI={10.1094/PDIS.2001.85.4.404}, abstractNote={ Fusarium head blight (FHB) can reduce yield of wheat and decrease the value of harvested grain by accumulation of detrimental toxins. Understanding the variability of the fungal population associated with infection could improve disease control strategies. Sixty-six isolates of Fusarium graminearum associated with FHB were collected in North Carolina and tested for in vitro growth rate, in vitro production of deoxynivalenol (DON) and zearalenone, and pathogenicity on three cultivars of soft red winter wheat. Significant differences among isolates were found for all three traits. Randomly Amplified Polymorphic DNA (RAPD) analysis revealed high levels of genotypic diversity among isolates. Isolates of F. graminearum, F. culmorum, and F. avenaceum acquired from the Pennsylvania State University Fusarium Center were included for comparison in all tests. In vivo levels of DON were measured for the five isolates associated with the highest levels of disease and the five isolates associated with the lowest levels of disease, and no significant differences were found. However, all ten isolates produced detectable levels of DON in vivo. Mean disease ratings ranged from 3.4 to 96.4%, in vitro (DON) levels ranged from 0 to 7176.2 ppm, and zearalenone ranged from 0 to 354.7 ppm, among isolates. A multiple regression model using in vitro growth, in vitro DON, and zearalenone production, collection location, wheat cultivar of isolate origin, plot, tillage conditions, and previous crop as independent variables and percent blighted tissue as the dependent variable was developed. The cumulative R2 value for the model equaled 0.27 with in vitro rate of growth making the largest contribution. Analysis of phenotype and genotype among isolates demonstrated diversity in a single plot, in a single location, and in North Carolina. Genotypic and phenotypic diversity were significant under both conventional and reduced tillage conditions, and diversity was high regardless of whether the previous crop had been a host or non-host for F. graminearum. These data indicate a variable pathogen population of F. graminearum exists in North Carolina, and members of this population can be both highly pathogenic on wheat and produce high levels of detrimental toxins, indicating a potential threat for problems with FHB within the state. }, number={4}, journal={PLANT DISEASE}, author={Walker, SL and Leath, S and Hagler, WM and Murphy, JP}, year={2001}, month={Apr}, pages={404–410} } @article{navarro_murphy_leath_shi_2000, title={Registration of NC97BGTAB9 and NC97BGTAB10 wheat germplasm lines resistant to powdery mildew}, volume={40}, number={5}, journal={Crop Science}, author={Navarro, R. A. and Murphy, J. P. and Leath, S. and Shi, A.}, year={2000}, pages={1508–1509} } @article{zhou_jellen_murphy_1999, title={Progenitor germplasm of domesticated hexaploid oat}, volume={39}, ISSN={["0011-183X"]}, DOI={10.2135/cropsci1999.0011183X003900040042x}, abstractNote={Cultivated hexaploid oat (Avena sativa L. and A. byzantina C. Koch) is classified as a secondary crop, i.e., derived from weeds of the primary cereal domesticates of the Near East. Avena sterilis L., the oldest hexaploid oat, is the putative progenitor of all other cultivated and wild hexaploid oat species. The objectives of this research were to gain insight into the origin of cultivated hexaploid oat by means of random amplified polymorphic DNA (RAPI)) marker variation and the distribution of the 7C‐17 intergenomic chromosomal translocation in cultivated and progenitor accessions. Cluster analyses based on 248 polymorphic RAPD markers found close association between several A. sterilis accessions from the Iran‐Iraq‐Turkey region and cultivated accessions. Genotypes within this group of cultivated and progenitor accessions were divided into those with the 7C‐17 translocation (A. sativa and A. sterilis) and those without the translocation (A. byzantina and A. sterilis). The results suggested that all cultivated hexaploids are derived from progenitor germplasm from Southwest Asia, present‐day Iran, Iraq, and Turkey. At least two paths of domestication occurred: one from A. sterilis with the translocation to A. sativa and one from A. sterilis without the translocation to A. byzantina.}, number={4}, journal={CROP SCIENCE}, author={Zhou, X and Jellen, EN and Murphy, JP}, year={1999}, pages={1208–1214} } @article{murphy_leath_huynh_navarro_shi_1999, title={Registration of NC97BGTD7 and NC97BGTD8 wheat germplasms resistant to powdery mildew}, volume={39}, ISSN={["0011-183X"]}, DOI={10.2135/cropsci1999.0011183X003900030066x}, abstractNote={and Ma. Saluda contains the Pm3a gene (3) and was susceptible in all greenhouse and evaluations conducted in the development of the germplasms. The direct diploid to hexaploid transfer methodology followed during backcrossing was similar to that outlined by Gill and Raupp (1). We utilized A-genome diploids as donor parents in place of the D-genome diploids described in that study. The hexaploid x diploid cross, Fj embryo rescue, and development of BC,F,, BC^, and BC2F2 seed were conducted during the 1988 to 1991 winter greenhouse seasons. Field selection using the pedigree breeding method was initiated with BC2F2 bulk populations in the 1991-1992 season. Natural powdery mildew epiphytotics occurred each year. Selection was primarily for mildew resistance during Feekes (2) Growth Stages 8 to 10.5, but whenever possible additional selection for heading date, plant height, and straw strength was conducted using the Saluda phenotype as the benchmark. Each germplasm line traces to a single headrow harvested in 1996. Laboratory evaluations for powdery mildew resistance using the detached leaf technique were conducted during development of these germplasms and again just prior to release. Laboratory evaluations were completed with 2-cm pieces of the primary leaves floated on 0.5% water agar amended with 50 mg L~' benzimidazole and evaluated as summarized elsewhere (3). Each line was tested for homogeneity by inoculating two replicate leaf pieces from 16 plants with four distinct isolates. Line NC96BGTA6 had 3.8% susceptible offtypes, whereas NC96BGTA4 and NC96BGTA5 were homogeneous. In addition, the three germplasms were inoculated with 30 isolates of the powdery mildew fungus with distinct differences in virulence formula and aggressiveness. These isolates had virulence to all previously identified alleles for powdery mildew resistance, with the possible exception ofPmlS. NC96BGTA4, NC96BGTA5, and NC96BGTA6 showed susceptible reactions to the 6, 0, and 1 isolates, respectively. None exhibited a susceptible reaction to commonly occurring isolates. Data and pedigree analysis showed that these germplasms contained at least one resistance gene in addition to Pm3a. Small quantities of seed (2 g) of each germplasm line are available upon written request to the corresponding author. Appropriate recognition of source should be given if this germplasm contributes to research or development of new cultivars.}, number={3}, journal={CROP SCIENCE}, author={Murphy, JP and Leath, S and Huynh, D and Navarro, RA and Shi, A}, year={1999}, pages={884–885} } @article{shi_leath_murphy_1998, title={A major gene for powdery mildew resistance transferred to common wheat from wild einkorn wheat}, volume={88}, ISSN={["0031-949X"]}, DOI={10.1094/PHYTO.1998.88.2.144}, abstractNote={ A major gene for resistance to wheat powdery mildew (Blumeria graminis f. sp. tritici = Erysiphe graminis f. sp. tritici) has been successfully transferred into hexaploid common wheat (Triticum aestivum, 2n = 6x = 42, AABBDD) from wild einkorn wheat (Triticum monococcum subsp. aegilopoides, 2n = 2x = 14, AA). NC96BGTA5 is a germ plasm line with the pedigree Saluda × 3/PI427662. The response patterns for powdery mildew resistance in NC96BGTA5 were tested with 30 differential isolates of B. graminis f. sp. tritici, and the line was resistant to all tested isolates. The analyses of P1, P2, F1, F2, and BC1F1 populations derived from NC96BGTA5 revealed two genes for wheat powdery mildew resistance in the NC96BGTA5 line. One gene, Pm3a, was from its recurrent parent Saluda, and the second was a new gene introgressed from wild einkorn wheat. The gene was determined to be different from Pm1 to Pm21 by gene-for-gene and pedigree analyses. The new gene was identified as linked to the Pm3a gene based on the F2 and BC1F1 populations derived from a cross between NC96BGTA5 and a susceptible cultivar NK-Coker 68-15, and the data indicated that the gene was located on chromosome 1A. It is proposed that this new gene be designated Pm25 for wheat powdery mildew resistance in NC96BGTA5. Three random amplified polymorphic DNA markers, OPX061050, OPAG04950, and OPAI14600, were found to be linked to this new gene. }, number={2}, journal={PHYTOPATHOLOGY}, author={Shi, AN and Leath, S and Murphy, JP}, year={1998}, month={Feb}, pages={144–147} } @article{murphy_leath_huynh_navarro_shi_1998, title={Registration of NC96BGTD1, NC96BGTD2, and NC96BGTD3 wheat germplasm resistant to powdery mildew}, volume={38}, ISSN={["0011-183X"]}, DOI={10.2135/cropsci1998.0011183X003800020097x}, abstractNote={graminis Pers.:Pers.) and common root rot [caused primarily by Bipolaris sorokiniana (Sacc. in Sorok.) Shoem.]. The germplasm line has grain yield, days to maturity, test weight, kernel weight, grain protein content, and gluten strength similar to Neepawa and the recurrent parent BW90. P8913-V2A5 is heterogeneous for leaf rust reaction (caused by P. recondita Roberge ex Desmaz.) and, at an average height of 104 cm, is 5 cm shorter than Neepawa. HY358 and HY320, the recurrent parents of P8917-B4D4 and P8921-Q4C5, are high-yielding wheat cultivars with medium protein content, gluten strength, and kernel hardness. P8917-B4D4 is a white-seeded and P8921-Q4C5 is a red-seeded germplasm line. P8917-B4D4 has a resistant reaction to loose smut, a moderately resistant reaction to stem rust and common root rot, and a moderately resistant to moderately susceptible reaction to leaf rust. Apart from test weight similar to Neepawa, P8917-B4D4 has higher grain yield and kernel weight, and requires about 4 d more to mature. Grain protein content is less, and height is 12 cm shorter than Neepawa. P8921-Q4C5 has a resistant reaction to loose smut and is moderately resistant to stem rust and common root rot. Compared with Neepawa, P8921-Q4C5 has similar test weight, greater grain yield, a heavier kernel weight, and more resistance to leaf rust (resistant to moderately resistant); it is about 3 d later to mature. Grain protein content is less and height is 13 cm shorter than Neepawa. Small amounts of seed, as well as more detailed information on the performance of the germplasm lines BW90, HY358, and HY424, are available from the corresponding author.}, number={2}, journal={CROP SCIENCE}, author={Murphy, JP and Leath, S and Huynh, D and Navarro, RA and Shi, A}, year={1998}, pages={570–571} } @article{walker_leath_murphy_lommel_1998, title={Selection for resistance and tolerance to oat mosaic virus and oat golden stripe virus in hexaploid oats}, volume={82}, ISSN={["0191-2917"]}, DOI={10.1094/PDIS.1998.82.4.423}, abstractNote={ Coker 716, a hexaploid oat cultivar resistant to both oat mosaic virus (OMV) and oat golden stripe virus (OGSV) was crossed to three susceptible cultivars (Brooks, Madison, and Tech) to form three individual populations. Individual breeding lines were derived from each cross in the F2 generation and tested in plots consisting of equally spaced individual hills in OMV- and OGSV-infested soils and non-infested soils to evaluate resistance and yield loss of individual lines. Foliar symptoms, harvest index, and yield loss were examined as selection criteria for resistant genotypes. The study was conducted over 2 years at two North Carolina locations that differed in soil type and climate. Multiple regression models describing yield loss in each cross due to rating, year, and location were calculated. Coefficients of multiple determination in these models ranged from 0.39 to 0.51. Yield loss ranged from 39 to 60% among different crosses. Infection by OMV and OGSV accounted for the majority of yield loss in two of the populations. Disease severity varied widely over years and locations. The results suggest that selection of lines with symptomatic tissue of 10% or less, or selection of tolerant lines, is needed for breeding progress. }, number={4}, journal={PLANT DISEASE}, author={Walker, SL and Leath, S and Murphy, JP and Lommel, SA}, year={1998}, month={Apr}, pages={423–427} } @article{senior_murphy_goodman_stuber_1998, title={Utility of SSRs for determining genetic similarities and relationships in maize using an agarose gel system}, volume={38}, ISSN={["0011-183X"]}, DOI={10.2135/cropsci1998.0011183X003800040034x}, abstractNote={Among maize (Zea maize L.) breeders, there is a heightened awareness of the necessity for both maintaining genetic diversity for crop improvement and improving the quality of genetic resource management. Restriction fragment length polymorphisms (RFLPs) and isozymes can serve as genetic markers for estimating divergence or diversity; however, the limited number of polymorphic isozyme loci available and the labor intensive and time consuming nature of RFLPs make their use for this purpose prohibitive. Simple sequence repeats (SSRs), when resolved using agarose gels, may be a viable and costeffective alternative to RFLPs and isozymes. Ninety‐four elite maize inbred lines, representative of the genetic diversity among lines derived from the Corn Belt Dent and Southern Dent maize races, were assayed for polymorphism at 70 SSR marker loci using agarose gels. The 365 alleles identified served as raw data for estimating genetic similarities among these lines. The patterns of genetic divergence revealed by the SSR polymorphisms were consistent with known pedigrees. A cluster analysis placed the inbred lines in nine clusters that correspond to major heterotic groups or market classes for North American maize. A unique fingerprint for each inbred line could be obtained from as few as five SSR loci. The utility of polymerase chain reaction (PCR)‐based markers such as SSRs for measuring genetic diversity, for assigning lines to heterotic groups and for genetic fingerprinting equals or exceeds that of RFLP markers, a property that may prove a valuable asset for a maize breeding program.}, number={4}, journal={CROP SCIENCE}, author={Senior, ML and Murphy, JP and Goodman, MM and Stuber, CW}, year={1998}, pages={1088–1098} } @article{murphy_griffey_finney_leath_1997, title={Agronomic and grain quality evaluations of Triticum aestivum x Aegilops tauschii backcross populations}, volume={37}, ISSN={["0011-183X"]}, DOI={10.2135/cropsci1997.0011183X003700060047x}, abstractNote={Aegilops tauschii Coss., a diploid progenitor of common wheat, Triticum aestivum L., is a valuable source of pest resistance alleles. However, interspecific populations generated for pest‐resistant germplasm development may contain beneficial alleles for other important traits. The objective of this research was to evaluate eight agronomic and grain quality traits in three soft red winter wheat × Ae. tauschii backcross populations. A total of 385 BC2F2‐derived lines were grown at locations in North Carolina and Virginia for two seasons. Grain quality evaluations were conducted at the USDA‐ARS Soft Wheat Quality Laboratory. Fifty‐four percent of lines did not differ significantly from their recurrent parent, averaged over all eight traits. In general, distributions were negatively skewed for grain yield and test weight and positively skewed for heading date, plant height, flour protein concentration, and alkaline water retention capacity. Line distributions for flour yield and softness equivalent were population dependent. Twenty‐three lines were significantly superior to their recurrent parent for one or more grain quality traits and similar to the recurrent parent for all remaining traits. Researchers who generate interspecific T. aestivum × Ae. tauschii populations for pest‐resistant germplasm development can identify lines with beneficial alleles governing other traits in an acceptable cultivated background if the progeny undergo additional screening.}, number={6}, journal={CROP SCIENCE}, author={Murphy, JP and Griffey, CA and Finney, PL and Leath, S}, year={1997}, pages={1960–1965} } @article{murphy_navarro_leath_murphy_bowman_1997, title={Registration of 'Rodgers' oat}, volume={37}, ISSN={["0011-183X"]}, DOI={10.2135/cropsci1997.0011183X003700030073x}, abstractNote={Crop ScienceVolume 37, Issue 3 cropsci1997.0011183X003700030073x p. 1017-1017 Registration of Cultivars Registration of ‘Rodgers’ Oat J. P. Murphy, Corresponding Author J. P. Murphy [email protected] Dep. of Crop ScienceCorresponding author ([email protected]).Search for more papers by this authorR. A. Navarro, R. A. Navarro Dep. of Crop ScienceSearch for more papers by this authorS. Leath, S. Leath USDA-ARS and Dep. of Plant Pathology, North Carolina State Univ., Raleigh, NC, 27695-7629Search for more papers by this authorC. F. Murphy, C. F. Murphy USDA-ARS, BARC-West, Beltsville, MD, 20705Search for more papers by this authorD. T. Bowman, D. T. Bowman Dep. of Crop ScienceSearch for more papers by this author J. P. Murphy, Corresponding Author J. P. Murphy [email protected] Dep. of Crop ScienceCorresponding author ([email protected]).Search for more papers by this authorR. A. Navarro, R. A. Navarro Dep. of Crop ScienceSearch for more papers by this authorS. Leath, S. Leath USDA-ARS and Dep. of Plant Pathology, North Carolina State Univ., Raleigh, NC, 27695-7629Search for more papers by this authorC. F. Murphy, C. F. Murphy USDA-ARS, BARC-West, Beltsville, MD, 20705Search for more papers by this authorD. T. Bowman, D. T. Bowman Dep. of Crop ScienceSearch for more papers by this author First published: 01 May 1997 https://doi.org/10.2135/cropsci1997.0011183X003700030073xCitations: 1AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume37, Issue3May–June 1997Pages 1017-1017 RelatedInformation}, number={3}, journal={CROP SCIENCE}, author={Murphy, JP and Navarro, RA and Leath, S and Murphy, CF and Bowman, DT}, year={1997}, pages={1017–1017} } @article{murphy_phillips_1993, title={ISOZYME VARIATION IN CULTIVATED OAT AND ITS PROGENITOR SPECIES, AVENA-STERILIS L}, volume={33}, ISSN={["0011-183X"]}, DOI={10.2135/cropsci1993.0011183X003300060048x}, abstractNote={Effective identification of wild accessions with potential to enhance variation for complex, Iow‐heritability traits is a prerequisite to broader utilization of conserved genetic resources. In two previous studies, 23 enzyme systems were assayed in 405 oat cultivars (Avena sativa L. and A. byzantina C. Koch) and in 1005 accessions of the progenitor species. A. sterilis L. The objectives of the present report were to (i) compare isozymic variation in cultivated oat with a broad geographical sample of accessions of the progenitor species and (ii) propose strategy to assist in the efficient sampling of progenitor germplasm by North American oat breeders. Avena sterilis displayed a greater level of isozymic diversity compared to cultivated germplasm based upon number and frequencies of variants. Three sampling strategies are discussed whereby a representative core of A. sterilis accessions could be selected from the progenitor germplasm pool. A combined strategy is outlined that incorporates elements of all three, with selection of accessions from (i) the center of isozymic diversity (Turkey), (ii) six clusters of A. sterilis accessions identified by multivariate analysis of genetic distances between accessions without regard to provenance data, and (iii) those accessions with variants present at intermediate to high frequencies in A. sterilis from individual countries or clusters yet absent in cultivated germplasm. Selected A. sterilis accessions could be used in combining ability analyses with cultivated germplasm. Subsequent, more extensive, exploitation of the germplasm collection might be based on results from these exploratory evaluations of breeding potential.}, number={6}, journal={CROP SCIENCE}, author={MURPHY, JP and PHILLIPS, TD}, year={1993}, pages={1366–1372} } @article{murphy_navarro_leath_murphy_1993, title={REGISTRATION OF YEATS OAT}, volume={33}, ISSN={["0011-183X"]}, DOI={10.2135/cropsci1993.0011183X003300060064x}, abstractNote={Crop ScienceVolume 33, Issue 6 cropsci1993.0011183X003300060064x p. 1408-1408 Registration of Cultivars Registration of ‘Yeats’ Oat J. P. Murphy, Corresponding Author J. P. Murphy n/[email protected] Corresponding author.Search for more papers by this authorR. A. Navarro, R. A. NavarroSearch for more papers by this authorS. Leath, S. LeathSearch for more papers by this authorC. F. Murphy, C. F. MurphySearch for more papers by this author J. P. Murphy, Corresponding Author J. P. Murphy n/[email protected] Corresponding author.Search for more papers by this authorR. A. Navarro, R. A. NavarroSearch for more papers by this authorS. Leath, S. LeathSearch for more papers by this authorC. F. Murphy, C. F. MurphySearch for more papers by this author First published: 01 November 1993 https://doi.org/10.2135/cropsci1993.0011183X003300060064xAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article. Volume33, Issue6November–December 1993Pages 1408-1408 RelatedInformation}, number={6}, journal={CROP SCIENCE}, author={MURPHY, JP and NAVARRO, RA and LEATH, S and MURPHY, CF}, year={1993}, pages={1408–1408} } @article{murphy_navarro_leath_murphy_1993, title={Registration of 'Mollybloom' barley}, volume={33}, DOI={10.2135/cropsci1993.0011183x003300060056x}, abstractNote={Crop ScienceVolume 33, Issue 6 cropsci1993.0011183X003300060056x p. 1402-1403 Registration of Cultivars Registration of ‘Mollybloom’ Barley J. P. Murphy, Corresponding Author J. P. Murphy n/a@.dne Corresponding author.Search for more papers by this authorR. A. Navarro, R. A. NavarroSearch for more papers by this authorS. Leath, S. LeathSearch for more papers by this authorC. F. Murphy, C. F. MurphySearch for more papers by this author J. P. Murphy, Corresponding Author J. P. Murphy n/a@.dne Corresponding author.Search for more papers by this authorR. A. Navarro, R. A. NavarroSearch for more papers by this authorS. Leath, S. LeathSearch for more papers by this authorC. F. Murphy, C. F. MurphySearch for more papers by this author First published: 01 November 1993 https://doi.org/10.2135/cropsci1993.0011183X003300060056xAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume33, Issue6November–December 1993Pages 1402-1403 RelatedInformation}, number={6}, journal={Crop Science}, author={Murphy, J. P. and Navarro, R. A. and Leath, S. and Murphy, C. F.}, year={1993}, pages={1402} } @article{murphy_navarro_leath_murphy_1993, title={Registration of 'Mulligan' barley}, volume={33}, DOI={10.2135/cropsci1993.0011183x003300060055x}, abstractNote={Crop ScienceVolume 33, Issue 6 cropsci1993.0011183X003300060055x p. 1402-1402 Registration of Cultivars Registration of ‘Mulligan’ Barley J. P. Murphy, Corresponding Author J. P. Murphy n/a@.dne Corresponding author.Search for more papers by this authorR. A. Navarro, R. A. NavarroSearch for more papers by this authorS. Leath, S. LeathSearch for more papers by this authorC. F. Murphy, C. F. MurphySearch for more papers by this author J. P. Murphy, Corresponding Author J. P. Murphy n/a@.dne Corresponding author.Search for more papers by this authorR. A. Navarro, R. A. NavarroSearch for more papers by this authorS. Leath, S. LeathSearch for more papers by this authorC. F. Murphy, C. F. MurphySearch for more papers by this author First published: 01 November 1993 https://doi.org/10.2135/cropsci1993.0011183X003300060055xAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume33, Issue6November–December 1993Pages 1402-1402 RelatedInformation}, number={6}, journal={Crop Science}, author={Murphy, J. P. and Navarro, R. A. and Leath, S. and Murphy, C. F.}, year={1993}, pages={1402} }