Genome-Wide Association Study in Bread Wheat Identifies Loci for Grain Protein Concentration and Test Weight

Wheat is one of the top three staple grains in the world, along with rice and maize. Bread wheat (Triticum aestivum) is an allohexaploid (AABBDD) with a large (17 Gb) genome for which mapping efforts have been underway for many years. Wheat breeders list grain protein concentration and test weight as the principal grain traits of interest to wheat producers. The Triticeae-Coordinated Agricultural Project's winter wheat association mapping panel of 299 modern and historically important cultivars and lines adapted to the United States Great Plains region was grown in four environments during the 2011-2012 and 2012-2013 growing seasons. Phenotypic data were collected for a variety of agronomic and grain quality traits. A genome-wide association study (GWAS) found several putative loci associated with grain protein concentration on chromosomes 2A, 4A, and 2D, and for test weight on chromosomes 1B, 2B, 3B, and 4B.