Drought, especially after anthesis, is one of the main stresses in wheat production in Mediterranean regions. An experiment was conducted for assessing tolerance of 5 bread wheat genotypes to terminal drought. Experimental design was split plot on the basis of randomized complete block in four replications in Research Farm of agricultural and natural resources university of Ramin in Ahvaz, Iran. Three levels of irrigation include S1 (mild stress), S2 (severe stress), and S- (without stress) as main plots, and 5 genotypes of bread wheat including G1 (Chamran), G2 (Falat), G3 (Verinak), G4 (Kavir), and G5 (Shole) as sub plot. Four drought tolerance indices, stress tolerance (TOL), Stress Tolerance Index (STI), Stress Susceptibility Index (SSI) and Mean Productivity (MP) were used. Whereas the indicates that have the most correlation with grain yield in different conditions are the best index for selection of tolerance genotypes against drought stress, there for (STI) and (MP) was selected for classify of genotypes. There was a significant and positive correlation of (Yp) and (Ys1) and (Ys2) with (MP and STI). Totally based on these indices genotypes of Chamran were the most desirable genotypes for both mild stress and severe stress environments.
