Identifying Quantitative Trait Loci for Economic Traits in an Elite Soft Red Winter Wheat Population

Abstract

Genotyping‐by‐sequencing (GBS), reduces genotyping costs and allows breeders to genotype large populations with thousands of markers. Genome‐wide association studies with GBS markers can be used to identify quantitative trait loci (QTL) for important traits in elite populations of soft red winter wheat (SRWW; Triticum aestivum L.). Our objective was to identify potential QTL for grain yield (GY), Fusarium head blight resistance (FHB), flour yield (FY), and softness equivalence (SE) in a set of 470 elite SWRR wheat lines that were genotyped with 33,169 GBS markers and phenotyped in multiple environments. For all traits, we found lines that were phenotypically superior to the elite checks. We identified four FHB QTL, nine QTL for quality, and 14 QTL for with R2 values ranging from 1.6 to 3.5%. The QTL with the largest effect for FHB resistance reduced disease by 1.76%. For quality, the largest‐effect QTL increased FY and SE by 0.37 and 0.67%, respectively. For GY the QTL with the largest effect in Wooster, OH, increased GY by 129.6 kg ha−1, for northwest Ohio, the largest‐effect QTL increased GY by 67.2 kg ha−1, and the largest‐effect QTL for GY over all environments increased GY by 48.8 kg ha−1. While marker‐assisted selection (MAS) for these QTL could be used to improve these traits, the preponderance of genetic variation appeared to be controlled by genes with small effect, suggesting that MAS should be used as a supplement to genomic selection.