Agronomic Characteristics of Spring Wheat Accessions From the USDA National Small Grains Collection Evaluated Under Drought and Low Nitrogen Environments.

Plant breeders seek to increase crop yields and improve end-use quality.  A large obstacle faced by modern breeders is the lack of new germplasm which can maintain high yield and quality in stress environments.  In this study we evaluated 540 spring wheat accessions from the USDA's National Small Grain Collection under limited water and deficient nitrogen conditions.  We were able to identify accessions with tolerance to deficient nitrogen and water stress in terms of yield, grain quality, and other related agronomic traits.  Marker analysis identified several significant marker-trait associations related to water and nitrogen use efficiency.  This study shows the value of germplasm collections as a source for novel genes not present in currently cultivated spring wheat cultivars.