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Soft 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. [ABSTRACT FROM AUTHOR]

'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. [ABSTRACT FROM AUTHOR]

Background: Climate change, including higher temperatures (HT) has a detrimental impact on wheat productivity and modeling studies predict more frequent heat waves in the future. Wheat growth can be impaired by high daytime and nighttime temperature at any developmental stage, especially during the grain filling stage. Leaf chlorophyll content, leaf greenness, cell membrane thermostability, and canopy temperature have been proposed as candidate traits to improve crop adaptation and yield potential of wheat under HT. Nonetheless, a significant gap exists in knowledge of genetic backgrounds associated with these physiological traits. Identifying genetic loci associated with these traits can facilitate physiological breeding for increased yield potential under high temperature stress condition in wheat. Results: We conducted genome-wide association study (GWAS) on a 236 elite soft wheat association mapping panel using 27,466 high quality single nucleotide polymorphism markers. The panel was phenotyped for three years in two locations where heat shock was common. GWAS identified 500 significant marker-trait associations (MTAs) (p ≤ 9.99 × 10− 4). Ten MTAs with pleiotropic effects detected on chromosomes 1D, 2B, 3A, 3B, 6A, 7B, and 7D are potentially important targets for selection. Five MTAs associated with physiological traits had pleiotropic effects on grain yield and yield-related traits. Seventy-five MTAs were consistently expressed over several environments indicating stability and more than half of these stable MTAs were found in genes encoding different types of proteins associated with heat stress. Conclusions: We identified 500 significant MTAs in soft winter wheat under HT stress. We found several stable loci across environments and pleiotropic markers controlling physiological and agronomic traits. After further validation, these MTAs can be used in marker-assisted selection and breeding to develop varieties with high stability for grain yield under high temperature. [ABSTRACT FROM AUTHOR]

Moderate heat stress accompanied by short episodes of extreme heat during the post-anthesis stage is common in most US wheat growing areas and causes substantial yield losses. Sink strength (grain number) is a key yield limiting factor in modern wheat varieties. Increasing spike fertility (SF) and improving the partitioning of assimilates can optimize sink strength which is essential to improve wheat yield potential under a hot and humid environment. A genome-wide association study (GWAS) allows identification of novel quantitative trait loci (QTLs) associated with SF and other partitioning traits that can assist in marker assisted breeding. In this study, GWAS was performed on a soft wheat association mapping panel (SWAMP) comprised of 236 elite lines using 27,466 single nucleotide polymorphisms (SNPs). The panel was phenotyped in two heat stress locations over 3 years. GWAS identified 109 significant marker-trait associations (MTAs) (p ≤ 9.99 x 10−5) related to eight phenotypic traits including SF (a major component of grain number) and spike harvest index (SHI, a major component of grain weight). MTAs detected on chromosomes 1B, 3A, 3B, and 5A were associated with multiple traits and are potentially important targets for selection. More than half of the significant MTAs (60 out of 109) were found in genes encoding different types of proteins related to metabolism, disease, and abiotic stress including heat stress. These MTAs could be potential targets for further validation study and may be used in marker-assisted breeding for improving wheat grain yield under post-anthesis heat stress conditions. This is the first study to identify novel QTLs associated with SF and SHI which represent the major components of grain number and grain weight, respectively, in wheat. [ABSTRACT FROM AUTHOR]

Abstract The varietal differences in pre-harvest sprouting (PHS) resistance and associated grain characteristics have yet to be understood. We tested the grains of 125–166 soft winter (SW) wheat varieties grown for three years for falling number (FN), α-amylase activity, and degree of sprouting (DS) under field sprouting (FS) and spike wetting conditions, and determined the characteristics of grain produced under non-FS conditions for two years. Eleven to 31 varieties exhibited FNs higher than 200 under spike wetting conditions, and 16 to 99 varieties exhibited FNs above 300 under FS conditions. Red wheat varieties showed significantly (p < 0.05) higher FNs than soft white wheat varieties for the grains produced under FS conditions in 2015 and 2017 and subjected to spike wetting in 2017. Awned varieties showed significantly (p < 0.05) lower FNs and higher DS values than awnless varieties when subjected to spike wetting in 2016. Falling number, α-amylase activity, and DS of grain produced under FS in 2015, 2016 and 2017 exhibited significant correlations with test weight (TW) (p < 0.01) of grain produced under non-FS conditions in 2016 and 2017. Five awnless red wheat varieties exhibited relatively high FNs, even under FS and spike wetting conditions. Highlights • Soft wheat varieties show large differences in pre-harvest sprouting resistance. • Seed coat color and awn presence of wheat affect pre-harvest sprouting resistance. • High test weight potential of wheat is linked to pre-harvest sprouting resistance. [ABSTRACT FROM AUTHOR]

Knowledge of HMW-GS composition and rye translocations of U.S. eastern soft winter (ESW) wheat, and their associations with protein characteristics will be helpful for the identification and selection of genotypes possessing the appropriate gluten strength for wheat-based products. HMW-GS composition and rye translocations of 149 ESW wheat varieties and their relationships with lactic acid solvent retention capacity and SDSS volume were determined. Subunits 2*, 7 + 8 and 2 + 12 are the predominant HMW-GSs in ESW wheat with frequencies of 72.7%, 47.7% and 36.7%, respectively. Two rare subunits, 2.. at Glu-A1 locus and 2+12 1 at Glu-D1 locus, were detected for the first time in ESW wheat, with frequencies of 1.6% and 21.9%, respectively. 1BL/1RS and 1AL/1RS translocations were observed in 18.8% and 10.9% of ESW wheat, respectively. Subunits 13 + 16, 5 + 10, and the absence of 1BL/1RS translocation showed associations with strong protein strength, whereas subunits 2+12 1 were associated with weak protein strength. Four HMW-GS profiles (2*, 7 + 8, 2+12 1), (2*, 7 + 8, 5 + 10), (2*, 7 + 9, 2 + 12), and (2*, 7 + 8, 2 + 12) were predominantly observed in 50.1% of ESW wheat. ESW wheat genotypes carrying subunits 13 + 16 or 7* + 8 at Glu-B1 locus and 5 + 10 at Glu-D1 locus without 1BL/1RS translocation are expected to produce wheat grain containing strong-gluten proteins. Image 1 • Wide variation in HMW-GS and rye translocations among U.S. soft winter wheat (SWW). • Subunits 2..at Glu-A1 and 2+12 1 at Glu-D1 were observed for the first time in SWW. • Glu-D1 had the highest genetic diversity and the greatest effect on protein strength. • Subunits 2+12 1 with a frequency of 21.9% were associated with weak protein strength. [ABSTRACT FROM AUTHOR]