@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{guedira_maloney_xiong_petersen_murphy_marshall_johnson_harrison_brown-guedira_2014, title={Vernalization Duration Requirement in Soft Winter Wheat is Associated with Variation at the VRN-B1 Locus}, volume={54}, ISSN={["1435-0653"]}, DOI={10.2135/cropsci2013.12.0833}, abstractNote={ABSTRACTGenetic variation in the factors controlling flowering in wheat (Triticum aestivum L.) allow it to be grown in a wide range of environments. The aim of this study was to identify genetic determinants of flowering time in winter wheat cultivars adapted to regions of the United States differing in latitude and the duration of cold temperatures during winter. Quantitative trait locus (QTL) analysis was performed in a recombinant inbred line (RIL) population from the cross between cultivars NC‐Neuse and AGS 2000 that are adapted to the Mid‐Atlantic and Southeastern regions, respectively. We identified a QTL for heading date (HD) in the greenhouse after 4 wk of vernalization, designated Qvdr.nc‐5BL, which also had a large effect on winter dormancy release and HD when the population was evaluated in the field at locations in North Carolina, Georgia, and Louisiana during 2012 and North Carolina during 2013. However, Qvdr.nc‐5BL did not have a significant effect on HD in greenhouse grown plants vernalized for 8 wk or in plants grown in the field at Raleigh, NC during 2011. In those environments where Qvdr.nc‐5BL was not significant, a region on chromosome 2B, probably associated with the Ppd‐B1 locus, was determined to have a HD effect. Interrogation of the population with gene‐based markers for Vrn‐B1 and Ppd‐B1 suggests that these loci are major determinants of HD in winter wheat and are important for adaptation to diverse growing environments.}, number={5}, journal={CROP SCIENCE}, author={Guedira, Mohammed and Maloney, Peter and Xiong, Mai and Petersen, Stine and Murphy, J. Paul and Marshall, David and Johnson, Jerry and Harrison, Steve and Brown-Guedira, Gina}, year={2014}, pages={1960–1971} } @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} } @inproceedings{advances in breeding for winter hardiness in oats_2009, booktitle={Proceedings of the Annual Meeting, American Society of Agronomy}, year={2009} } @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} }