Abstract
Requirements of barley grain protein concentration vary depending on the end‐use purpose of the grain. High protein levels are desired for high‐quality feed and food, whereas relatively low protein levels are preferred for malting. The current study evaluated variation of grain protein concentration and nitrogen (N) concentration in flag leaves among barley genotypes with diverse backgrounds. A panel of 79 spring barley genotypes was grown in field experiments under well‐watered and drought‐stressed conditions over two growing seasons. In each water regime, variation in flag leaf N concentration (only under drought‐stressed conditions), grain protein concentration, grain yield and other agronomic parameters was found among genotypes. Based on grain protein and flag leaf N concentration, four broad genotype categories were found: high values for both, low values for both, low grain protein with high flag leaf N and high grain protein with low flag leaf N. This grouping suggests variation in N remobilization from vegetative tissues to grain. Germplasm identified in the present study will enable further study of the mechanisms regulating protein accumulation in barley and contribute to the development of barley germplasm for various end uses.