Evaluation drought tolerance indices on the basis of physiological characteristics for different genotypes of barley in Esfahan region

In order to determine drought tolerance indices according to physiological characteristics for different genotypes of barley in Esfahan region, an experiment was conducted at Esfahan Agriculture Research Station in 2011 (Latitude 32o30/ N, longitude 51o49/ E, and 1541 m elevation). These two experiments laid out separately, by complete block design (RCBD) with 3 replications, in which, 10 genotypes were studied at drought stress condition (Irrigation disruption after emergence of spikes) and normal water irrigation. Indices including stress susceptibility index (SSI), stress tolerance index (STI), tolerance (TOL), mean productivity (MP) and geometric mean productivity (GMP) were calculated based on grain yield under stress and non-stress conditions. Yp had significant and positive correlation with TOL, SSI, MP and GMP. On the basis of indices, genotypes 3, 6 and 10 are the superior barley genotype with not only drought stress resistance, but also appropriate yield potential under both non-stress and limited irrigation conditions. MP, GMP and STI were the most desirable indices for screening drought tolerant genotypes.