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.

中文翻译：

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春大麦基因型籽粒和叶片氮素积累变化

大麦谷物蛋白质浓度的要求取决于谷物的最终用途。高质量的饲料和食品需要高蛋白质水平，而麦芽制造则需要相对较低的蛋白质水平。目前的研究评估了具有不同背景的大麦基因型中旗叶中谷物蛋白浓度和氮 (N) 浓度的变化。一组 79 种春大麦基因型在田间试验中在两个生长季节的水分充足和干旱胁迫条件下生长。在每个水分条件下，基因型之间发现旗叶氮浓度（仅在干旱胁迫条件下）、籽粒蛋白浓度、籽粒产量和其他农艺参数的变化。基于谷物蛋白和旗叶氮浓度，发现了四个广泛的基因型类别：两者都具有高值，两者都具有低值，低谷物蛋白与高旗叶 N 和高谷物蛋白与低旗叶 N。这种分组表明从营养组织到谷物的 N 再活化存在差异。本研究中鉴定的种质将有助于进一步研究调节大麦中蛋白质积累的机制，并有助于开发用于各种最终用途的大麦种质。