@article{balint-kurti_zwonitzer_wisser_carson_oropeza-rosas_holland_szalma_2007, title={Precise mapping of quantitative trait loci for resistance to southern leaf blight, caused by Cochliobolus heterostrophus race O, and flowering time using advanced intercross maize lines}, volume={176}, ISSN={["1943-2631"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-34548569322&partnerID=MN8TOARS}, DOI={10.1534/genetics.106.067892}, abstractNote={Abstract}, number={1}, journal={GENETICS}, author={Balint-Kurti, P. J. and Zwonitzer, J. C. and Wisser, R. J. and Carson, M. L. and Oropeza-Rosas, M. A. and Holland, J. B. and Szalma, S. J.}, year={2007}, month={May}, pages={645–657} }
 @article{ferguson_carson_2007, title={Temporal variation in Setosphaeria turcica between 1974 and 1994 and origin of races 1, 23, and 23N in the United States}, volume={97}, ISSN={["0031-949X"]}, DOI={10.1094/PHYTO-97-11-1501}, abstractNote={ Setosphaeria turcica causes northern leaf blight, an economically important disease of maize throughout the world. Survey collections of S. turcica isolates from 1974 to 1994 provided a unique opportunity to examine temporal diversity in the eastern United States. Two hundred forty-two isolates of S. turcica from maize were studied with random amplified polymorphic DNA (RAPD) markers, mating type, and virulence on maize differential inbred lines with known Ht resistance genes to examine changes over time. One hundred forty-nine RAPD haplotypes were identified. Nearly 20% of haplotypes recurred in more than one year. Race 0 isolates declined in frequency from 83% in 1974 to near 50% in the 1990s, most likely in response to the widespread deployment of Ht1 in commercial maize hybrids. Races 23 and 23N were present in the collection at low levels throughout the study period and were also found among isolates from Virginia in 1957. The frequency of MAT1-2 isolates increased sharply after 1979 and was associated with the emergence of race 1 during the same period. RAPD markers were used to investigate the genetic diversity among a subset of isolates collected in the United States from 1976 to 1982, the period in which this dramatic shift in race frequency occurred. Multilocus haplotypes were not exclusively associated with known races of S. turcica. Based on shared haplotypes and cluster analysis, race 1 isolates share greater similarity with race 0 than with 23 or 23N isolates, indicating race 1 probably evolved from multiple lineages of race 0. Sorghum spp.-infecting isolates share greater similarity with one another than with maize-infecting isolates and represent a distinct subgroup. }, number={11}, journal={PHYTOPATHOLOGY}, author={Ferguson, L. M. and Carson, M. L.}, year={2007}, month={Nov}, pages={1501–1511} }
 @article{balint-kurti_carson_2006, title={Analysis of quantitative trait loci for resistance to southern leaf blight in juvenile maize}, volume={96}, ISBN={0031-949X}, number={3}, journal={Phytopathology}, author={Balint-Kurti, P. J. and Carson, M. L.}, year={2006}, pages={221} }
 @article{carson_balint-kurti_blanco_millard_duvick_holley_hudyncia_goodman_2006, title={Registration of nine high-yielding tropical by temperate maize germplasm lines adapted for the southern USA}, volume={46}, ISSN={["1435-0653"]}, url={http://dx.doi.org/10.2135/cropsci2005.08-0283 http://search.ebscohost.com/login.aspx?direct=true{\&}db=agr{\&}AN=IND43883443{\&}site=ehost-live{\&}scope=site}, DOI={10.2135/cropsci2005.08-0283}, abstractNote={Nine maize (Zea mays L.) germplasm lines have been developed by the USDA GEM (Germplasm Enhancement of Maize) project (Reg no. GP-501–509, PI 639497–639505, see Table 1). The GEM project is a cooperative research effort to facilitate the introduction of exotic maize germplasm into U.S. breeding programs. It involves most U.S. maize breeding companies and many public cooperators (Pollak, 2003; Pollak and Salhuana, 2001; Goodman, 1999; Goodman and Carson, 2000; Goodman et al., 2000). Replicated breeding trials coordinated by North Carolina State University as part of the GEM project, and conducted by several public and private GEM cooperators, have identified nine superior F2S2 germplasm lines (S2 lines derived from an F2 population) containing 50% tropical germplasm by pedigree. When topcrossed to sister-line crosses or foundation-seed inbreds, these germplasm lines have yielded well in North Carolina and other southern corn growing regions of the USA in comparison to commercial check hybrids (i.e., their yields were either significantly higher or not statistically significantly different from the yields of the commercial check hybrids). They also performed at least as well as commercial check hybrids by several other criteria enumerated below. Table 1 shows the GEM names designated for these sources alongside their previous identifiers. The source of the tropical germplasm involved in these nine novel germplasm lines is the Brazilian population PE1 (also known as BR51403). PE1 is a composite of varieties from the state of Pernambuco, Brazil. The U.S. parent of the germplasm was a privately owned inbred line of the nonstiff stalk heterotic group. These germplasm lines were developed by selfing and selecting within variable F1s from crosses between the tropicalsource (i.e., different individuals from the PE1 population) and the U.S. inbred, in North Carolina under standard nursery conditions. F2 seed were bulked and used for a second selfing/ selection season in Homestead, FL. Nine hundred ninety F3 progenies, each derived from the self of a different F2 plant, were tested for per-se yield in unreplicated yield trials at the Sandhills Research Station in North Carolina in 1996. The top 10% were selected for further selfing and topcrossing in a winter nursery at Homestead, FL. All procedures were performed using ear-to-row methods (i.e., each row was planted with seeds from a single ear), except that F2 seeds planted at Homestead were bulked by pedigree (i.e., all the F2 seed from each tropical source 3 U.S. inbred were bulked). Germplasm lines were visually selected on the basis of resistance to lodging, early flowering, synchrony of silk and pollen production, and reduced plant and ear height. Topcross seed for initial yield trials were produced using the sister line cross FR992 3 FR1064 (provided by Illinois Foundation Seeds) as tester. These seed were used for yield trials in 15 test locations from Delaware to Georgia and as far west as Missouri over 2 yr (1997 and 1998). These states were Delaware (1 location), Georgia (3 locations), Kentucky (2 locations), Maryland (1 location), Missouri (2 locations), North Carolina (4 locations), Tennessee (1 location), Texas (1 location). The released germplasm lines were among the top performers in these tests. The seed moisture of the sources being registered was not significantly higher or was lower than the commercial hybrid check means in all cases and lodging was acceptable as well. These data are detailed in Table 1. Additional yield experiments were conducted with GEMS-0042, GEMS-0033, and GEMS-0037, top crossed to the stiff-stalk testers LH200 and LH244 and tested at several locations throughout the southern Corn Belt in 2001 and 2002. In these experiments the germplasm lines produced superior yields to elite hybrid checks, yielding between 9500 and 9800 kg ha compared with a hybrid check mean of 9390 kg ha21 (The checks in this case were Dekalb brand 687; Pioneer brands 30F33, 32K61, and 3165; NC320 3 T7; LH132 3 LH51 and LH200 3 LH262). In yield trials conducted in the mid-western Corn Belt (Iowa, Missouri, and Illinois) using LH200 and LH198 as testers, the yields of all of these germplasm lines were inferior to the hybrid check means. GEMS-0035 (8786 kg ha), GEMS-0039 (8704 kg ha), and GEMS-0042 (8604 kg ha) yielded best in top crosses with LH200, compared to the hybrid check mean of 9765 kg ha. (The checks in this case were Pioneer brands 31G98, 34B23, 33P66; LH198 3 LH185 and LH200 3 LH262). GEMS-0039 (9527 kg ha), GEMS-0036 (8817 kg ha) and GEMS-0037 (8786 kg ha21) yielded best in top crosses with LH198, compared with a hybrid check mean of 9602 kg ha. (The checks in this case were Pioneer brands 31G98, 34B23, 33P66; LH198 3 LH185 and LH200 3 LH262). These materials have a range of kernel colors; Orange and yellow (GEMS-0040), orange (GEMS-0037), yellow and yellow cap (GEMS-0036 and GEMS-0042), yellow cap (GEMS0035) and yellow (all others). A range of kernel textures are}, number={4}, journal={CROP SCIENCE}, author={Carson, M. L. and Balint-Kurti, P. J. and Blanco, M. and Millard, M. and Duvick, S. and Holley, R. and Hudyncia, J. and Goodman, M. M.}, year={2006}, pages={1825–1826} }
 @article{ferguson_carson_2004, title={Spatial diversity of Setosphaeria turcica sampled from the eastern United States}, volume={94}, ISSN={["1943-7684"]}, DOI={10.1094/PHYTO.2004.94.8.892}, abstractNote={ Randomly amplified polymorphic DNA (RAPD) markers and mating type were used to examine regional population structure of Setosphaeria turcica in the eastern United States. Of 251 maize-infecting isolates studied, 155 multilocus haplotypes were identified using 21 RAPD markers. Twelve isolates of the most common haplotype were identified from seven states and represented 5.2% of the sample. Although variation in genetic diversity was greatest within states rather than between either regions or states within regions, multidimensional scaling based on average taxonomic distances among state samples showed a close association of samples from IL, OH, IN, IA, MN, MI/WI, and NC. Isolates from GA/SC, VA/TN, PA/NY, and FL were distant from this core group that included midwestern states and NC and were distinct from one another. The high genotypic diversity, near equal mating type frequencies, and gametic phase equilibrium in samples from several states are inconsistent with a strictly clonal population. The population genetic structure of S. turcica is likely the result of both asexual and sexual reproduction. It is not clear whether sexual recombination actually occurs in the eastern United States or occurs elsewhere in tropical America and recombinant genotypes migrate to North America. }, number={8}, journal={PHYTOPATHOLOGY}, author={Ferguson, LM and Carson, ML}, year={2004}, month={Aug}, pages={892–900} }
 @article{carson_goodman_williamson_2002, title={Variation in aggressiveness among isolates of Cercospora from maize as a potential cause of genotype-environment interaction in gray leaf spot trials}, volume={86}, ISSN={["1943-7692"]}, DOI={10.1094/PDIS.2002.86.10.1089}, abstractNote={ The use of genetically resistant maize hybrids is the preferred means of control of gray leaf spot, caused by Cercospora zeae-maydis. One problem faced by maize breeders attempting to breed for resistance to gray leaf spot is the high degree of genotype-environment interactions observed in disease trials. In North Carolina gray leaf spot trials conducted at four locations in the western part of the state, we found consistent hybrid-location interactions over the 1995 and 1996 growing seasons. Isolates of C. zeae-maydis from those test locations were evaluated on the same hybrids used in the multilocation testing at a location in central North Carolina that does not have a history of gray leaf spot. The hybrid-isolate interactions observed in the isolate trial mirrored the hybrid-location effects seen in the multilocation testing. Most of the interactions arose from changes in the magnitude of differences between hybrids when inoculated with the isolates rather than from any change in hybrid ranking. Analysis of internal transcribed spacer-restriction fragment length polymorphisms (RFLPs) and mitochondrial rDNA RFLPs of those isolates and others revealed that both type I and type II sibling species of C. zeae-maydis, as well as C. sorghi var. maydis, are isolated from typical gray leaf spot lesions. Breeders should use the most aggressive isolates of C. zeae-maydis to maximize discrimination between genotypes in gray leaf spot trials. }, number={10}, journal={PLANT DISEASE}, author={Carson, ML and Goodman, MM and Williamson, SM}, year={2002}, month={Oct}, pages={1089–1093} }
 @article{carson_2001, title={Inheritance of resistance to phaeosphaeria leaf spot of maize}, volume={85}, DOI={10.1094/PDIS.2001.85.7.798}, abstractNote={ Phaeosphaeria leaf spot is a potentially important maize disease that has recently appeared in the continental United States in winter breeding nurseries in southern Florida. Inbred lines re lated to B73 are particularly susceptible to Phaeosphaeria leaf spot, whereas inbreds related to Mo17 are highly resistant. The inheritance of resistance to Phaeosphaeria leaf spot was studied in the parents, F1, F2, and backcross generations derived from the cross B73 × Mo17. A replicated experiment was conducted over two winter nursery seasons in a southern Florida nursery Individual plants in plots were evaluated for Phaeosphaeria leaf spot severity (0 to 9 scale) at the mid-dent stage of kernel development. Variation in segregating generations appeared continuous, so generation mean analysis was used. Additive and, to a lesser extent, dominance gene action were determined to play a role in the inheritance of reaction to Phaeosphaeria leaf spot There was no evidence for epistatic gene interactions. Heritabilities (both narrow and broad sense) were high (0.70 to 0.85) and the magnitude of genotype × environment interactions was low. Estimates of the number of effective factors (genes) involved in the inheritance of resistance ranged from three to four. Selection should be highly effective in developing inbred lines with adequate levels of resistance to Phaeosphaeria leaf spot. }, number={7}, journal={Plant Disease}, author={Carson, M. L.}, year={2001}, pages={798–800} }
 @article{goodman_moreno_castillo_holley_carson_2000, title={Using tropical maize germplasm for temperate breeding}, volume={45}, number={3}, journal={Maydica}, author={Goodman, M. M. and Moreno, J. and Castillo, F. and Holley, R. N. and Carson, M. L.}, year={2000}, pages={221–234} }
 @article{carson_1999, title={Vulnerability of US maize germ plasm to phaeosphaeria leaf spot}, volume={83}, ISSN={["1943-7692"]}, DOI={10.1094/PDIS.1999.83.5.462}, abstractNote={ Phaeosphaeria leaf spot (PLS) is a potentially important maize disease that has recently appeared in the continental United States in winter breeding nurseries in southern Florida. To better predict the potential of this newly introduced disease to inflict damage on the U.S. maize crop, 64 public and private inbred lines and 80 proprietary commercial maize hybrids representing the genetic diversity in the U.S. maize crop were evaluated for resistance to PLS in the 1996-97 and 1997-98 winter nursery seasons. Plots were evaluated for PLS severity (0 to 9 scale) at the early to mid dent stages of kernel development. Relatively few hybrids or inbreds were free from PLS at this growth stage. Inbred lines related to B73 were particularly susceptible to PLS. Relatively few commercial hybrids were as severely diseased as a susceptible check hybrid, indicating that U.S. maize production is not particularly vulnerable to damage from PLS at this time. However, the susceptibility of several widely used parental inbred lines makes PLS a potential concern to the seed industry should it become established in areas of hybrid seed production. }, number={5}, journal={PLANT DISEASE}, author={Carson, ML}, year={1999}, month={May}, pages={462–464} }
 @article{carson_1998, title={Aggressiveness and perennation of isolates of Cochliobolus heterostrophus from North Carolina}, volume={82}, ISSN={["0191-2917"]}, DOI={10.1094/PDIS.1998.82.9.1043}, abstractNote={ Selection occurring during the saprophytic or overwintering phase of the life cycle of Cochliobolus heterostrophus, the causal agent of southern leaf blight of maize, may be a factor in the persistence of apparently less aggressive isolates in the pathogen population. The relative aggressiveness and ability to perennate of 22 isolates of C. heterostrophus from North Carolina was measured in series of experiments. Significant differences in aggressiveness and percent perennation (overwintering survival) were observed. There was a weak but often significant negative correlation between the ability of isolates to persist on the soil surface and their aggressiveness. The ability of race O isolates to sporulate on senescent corn leaf discs was positively correlated with their aggressiveness. Selection against increased aggressiveness during overwintering does not appear sufficient by itself to counter selection for increased aggressiveness occurring during the pathogen's pathogenic phase. }, number={9}, journal={PLANT DISEASE}, author={Carson, ML}, year={1998}, month={Sep}, pages={1043–1047} }
 @article{carson_1995, title={A NEW GENE IN MAIZE CONFERRING THE CHLOROTIC HALO REACTION TO INFECTION BY EXSEROHILUM-TURCICUM}, volume={79}, ISSN={["0191-2917"]}, DOI={10.1094/PD-79-0717}, abstractNote={During recurrent selection in the maize synthetic BS19, S 1 lines exhibiting a unique lesion phenotype in response to infection with Exserohilum turcicum were observed. This phenotype, dubbed chlorotic halo, initially appears as dark orange-brown pigmented infection points that are later surrounded by a circular chlorotic halo about 1 cm in diameter. Most infection points retain this phenotype, although some later develop into the elongated, elliptical necrotic lesions typical of northern leaf blight (NLB). An inbred line derived from this initial selection was crossed to the susceptible inbred line A619 and the inheritance of the chlorotic halo reaction studied in advanced generations from this cross. Segregation ratios were consistent with the hypothesis that the chlorotic halo phenotype is controlled by a single recessive gene. This gene appears to be located on the short arm of chromosome 1 near the centromere, based upon reciprocal translocation mapping studies. The chlorotic halo reaction was expressed against races 0,1,23, and 23N of E. turcicum in the field. The effectiveness of the chlorotic halo gene in reducing losses to NLB remains to be demonstrated.}, number={7}, journal={PLANT DISEASE}, author={CARSON, ML}, year={1995}, month={Jul}, pages={717–720} }
 @article{carson_1995, title={INHERITANCE OF LATENT PERIOD LENGTH IN MAIZE INFECTED WITH EXSEROHILUM-TURCICUM}, volume={79}, ISSN={["0191-2917"]}, DOI={10.1094/PD-79-0581}, abstractNote={Extended latent period length is an important component of partial resistance of maize to northern leaf blight (NLB) caused by Exserohilum turcicum. Latent period length is easily measured on seedling plants under both field and greenhouse conditions and has been shown to be a relatively stable trait over a range of temperature and light conditions. The inheritance of latent period length was studied in F 2 and backcross generations of crosses of the experimental inbred line 69-1 (highly resistant, long latent period) and Mo17 (intermediately resistant, intermediate latent period) with the highly susceptible inbred line A632. Studies were conducted under both winter greenhouse conditions and in the field. Differences in mean latent periods between the two parental inbred lines varied from 14.1 days (A632 × 69-1; 1993 field experiment) to 1.8 days (A632 × Mo17; 1993 greenhouse experiment). Analysis of generation means of log-transformed latent periods revealed that over 92% of the variation among generation means could be explained by additive gene action and that dominance and epistatic effects were negligible. Heritability and gene number estimates were in agreement with previously published estimates for partial resistance to NLB measured as reduced disease severity on adult plants. Selection on some sort of progeny mean basis would probably be the most efficient and rapid means of selection for increased latent period and could potentially be more effective than selection for reduced NLB severity after anthesis}, number={6}, journal={PLANT DISEASE}, author={CARSON, ML}, year={1995}, month={Jun}, pages={581–585} }
 @article{carson_vandyke_1994, title={EFFECT OF LIGHT AND TEMPERATURE ON EXPRESSION OF PARTIAL RESISTANCE OF MAIZE TO EXSEROHILUM-TURCICUM}, volume={78}, ISSN={["0191-2917"]}, DOI={10.1094/PD-78-0519}, abstractNote={The effects of tight and temperature on the expression of major gene resistance in maize (Zea mays) to northern leaf blight (caused by Exserohilum turcicum) are well documented. However, their effects on the expression of partial resistance to the disease have not been studied. Six maize inbred lines, representing a wide range in levels of partial resistance to northern leaf blight, were evaluated for three components of partial resistance (incubation period, latent period, and sporulation intensity) in controlled environmental chambers representing a factorial arrangement of three temperature regimes (22/18 C, 26/22 C, and 30/26 C, day/night) and two light intensities (full light, 639 mu-E cntdot m-2 cntdot s-1, or half light, 320 mu-E cntdot m-2 cntdot s-1). Incubation and latent periods of inbred lines were consistently correlated, regardless of environmental conditions, and reflected the lines' levels of partial resistance. Although there was some relationship with partial resistance, sporulation intensity on inbred lines was highly variable, interacting with both temperature and light, and was greatly reduced at the 30/26 C temperature regime. Incubation or latent period length could be a useful measure of partial resistance of maize genotypes in greenhouse or growth chamber screenings of seedlings. Unlike major gene resistance, partial resistance expressed as an increased latent period appears to be a stable trait expressed over a wide range of temperature and tight conditions, although higher temperatures tended to increase the differences among genotypes.}, number={5}, journal={PLANT DISEASE}, author={CARSON, ML and VANDYKE, CG}, year={1994}, month={May}, pages={519–522} }
 @article{carson_1993, title={Relationship between parasitic and saprophytic fitness in Cochliobolus heterostrophus, cause of southern leaf blight of maize}, ISBN={0792323149}, journal={Durability of disease resistance}, publisher={Boston : Kluwer Academic Publishers}, author={Carson, M. L.}, editor={T. Jacobs and Parlevliet, J. E.Editors}, year={1993}, pages={308} }
 @article{carson_goodman_glawe_1991, title={Phaeosphaeria leaf spot of maize in Florida}, volume={75}, number={9}, journal={Plant Disease}, author={Carson, M. L. and Goodman, M. M. and Glawe, D. A.}, year={1991}, pages={968} }