Physiological and Agronomic Traits Related to Drought Tolerance in Barley Recombinant Inbred Line Population (Arigashar ×Igri)

To investigate important physiological and agronomic traits effective under drought conditions، their relationship with grain yield and to study drought tolerance and susceptibility indices in 169 barley recombinant inbred lines population of Arigashar/Igri، an experiment was carried out using alpha lattice design with two replications during 2011 to 2013 in Yazd and Birjand Research Stations under non - stress and drought stress conditions. During cropping seasons، lines were evaluated for physiological and agronomic traits. Combined analysis of variance of studied traits under two conditions showed significant differences among environments، genotypes and genotype × environment. Under drought stress conditions، harvest index (r = 0. 753**)، biological yield (r = 0. 572**)، canopy temperature (r = -0. 522**)، leaf relative water content (r = 0. 385**) and thousand kernel weight (r = 0. 339**) and under non-stress conditions، biological yield (r = 0. 572**) and harvest index (r = 0. 753**) had significant correlations with grain yield. Among physiological and agronomic traits which had high correlation with grain yield under drought stress conditions، canopy temperature can be utilized as an important selection criteria to identify drought tolerance genotype، because of its easy measurement in all breeding program stages. Based on grain yield under drought and non-stress conditions (Ys and Yp) and tolerance and susceptibility indices (SSI، TOL، MP، GMP، STI and Harm)، liens were classified in to four distinguished groups: a)high - yielding and drought tolerant، b) high - yielding and drought susceptible، c) semi tolerant and d) low - yielding and drought susceptible.