Evaluation of barley lines for drought tolerance under field condition

To evaluation of drought tolerance of advanced barley lines، 12 genotypes were grown at 2 experimental conditions of irrigated and drought condition at two growing seasons (2005-2007) in Gachsaran dry land agricultural research station. These experiments were performed as complete randomized block design (RCBD) with 3 replications. Data were collected from some agronomic and morpho–physiological traits and stress susceptibility-tolerance indices i. e. MP، GMP، HARM. STI، SSI and TOL. Results of combined analysis of variance for irrigated and stress conditions showed that the effects of year was non-significant and other effects (genotype and genotype × year) were significant at 1% level of probability. Average reduction of yield caused by drought stress was 28. 05%. Grain yield for drought condition ranged from 2. 682 t/ha (genotype L7) to 4. 071 t/ha (genotype L6) and for well watered status ranged from 4. 245 t/ha (L 4) to 5. 952 t/ha (L5). Two lines possessed higher tolerant indices i. e. 0. 89497 and 0. 88295 respectively than other genotypes. In consideration of grain yield in rain fed and irrigated conditions and different sensitivity/tolerance indices، principal components analysis and means of agronomic traits، genotype of L6 (average yield of 4. 996 t/ha) could be released as more adaptive genotype for warm and dry land regions. Moreover، STI and GMP were recommended as appropriate indices for improve grain yield under both optimum and stress conditions.