Abstract

Barley (Hordeum vulgare L.) is gaining a place among cereals as a food and feed for human and animal respectively in recent time because of its nutritive and malting properties. It is known that the crop can be grown efficiently even under harsh environment due to genetic makeup. Nitrogen an essential nutrient influences the growth and yield of barley. Among the constraints under this condition are water and nutrient, especially nitrogen availability. Therefore, an attempt has been made to understand the genetics of nitrogen metabolism vis-à-vis nitrogen utilization efficiency (NUE), nitrogen transportation, nitrogen assimilation, remobilization in different parts of plant as well as in grains. Thus for improvement of barley genotypes for low water, low nitrogen and high salinity i.e. harsh environment, a detailed analysis of genetic components are being undertaken for tolerant genotypes. Higher expression of the transporter HvNRT2/3 genes, especially HvNRT2.1, HvNRT2.5, and HvNRT3.3 also the expression levels of N assimilation genes including HvNIA1, HvNIR1, HvGS1_1, HvGS1_3, and HvGLU2 increased significantly nitrogen use efficiency(NUE) in barley. Partial sequences of five genes related to N-metabolism in barley (Hordeum vulgare L.) were obtained, i.e. nitrate reductase 1, glutamine synthetase 2, ferredoxin-dependent glutamate synthase, aspartate aminotransferase and asparaginase. Two to five haplotypes in each gene were discovered in a set of 190 varieties. Findings of 33 SNP markers allowed the genotyping of all these barley varieties consisting of spring and winter types. From correlation analyses it is confirmed that GOGAT was related to G6PDH; GDH and APX with PEPC in“100/1B” under moderate salinity; severe salinity is better correlated to GDH with G6PDH and PEPC.