effectiveness of stability indices for bread wheat genotypes selection to water deficit tolerant

in countries such as iran which will be faced water deficit as the main challenge in the future and the food production is going to be dependent to water recourses, wheat water-deficit tolerant and adapted genotypes release is one of the most important strategies under such a condition. in order to study the adaptation and terminal water deficit stress tolerance, fifteen bread wheat lines and chamran cultivar as the check were evaluated. this research was carried out at ahvaz, dezfool, zabol and darab, south warm region research stations, in 2007-08 and 2008-09, in two separated experiments (1-well-watered and 2- terminal water deficit stress), using complete randomized block design with three replications. data were analyzed and genotypes response was evaluated based on tolerance indices. results showed that the difference among stations, years, genotypes and double and triple effects of source variations were significant at 1% probability level. mean grain yield was 4300 kg/ha in first year, while grain yield increased significantly in second year and reached to 5692 kg/ha. mean grain yield were 5840 and 4591kg/ha under well-watered and terminal water deficit stress conditions, respectively. correlation coefficients among sti, gmp ،mp and k1sti were significant. correlation coefficient between slop of linear regression of grain yield in response to drought stress intensity and grain yield under terminal water deficit stress was positively and, with k2sti, tol and ssi was negatively significant. grain yield index, (yir) the proportion of grain yield of each genotype to grand mean of grain yield of all genotypes was the most important components to define grain yield in stepwise regression under both experiment conditions. according to the results of this research and based on tolerance indices, lines no. 2, 14 and 15 were selected as the high potential- terminal water deficit stress tolerant genotypes.