Genome-Wide Association Studies in the USDA Core Collection of Barley Germplasm

New sources of genetic diversity must to be incorporated into plant breeding programs if they are to continue increasing grain yield and quality in environments with increased incidences of abiotic and biotic stresses. The USDA National Small Collection (NSGC) contains one of the largest collections of barley germplasm in the world. A well-characterized subset of the NSGC representing 1,860 landraces and historical breeding materials from 94 countries (NSGC iCore) is being used for genome-wide association studies (GWAS). In particular, we are using GWAS to identify genomic regions determining a set of morphological (lemma color and aleurone color), agronomic (heading date, plant height and thousand kernel weight) and disease resistance (stripe rust, leaf scald, net blotch and Russian wheat aphid) traits. This approach will assist us to access the natural diversity available in the core collection and to accelerate its utilization for barley breeding.