Comparison of different methods of stability evaluation in bread wheat genotypes under drought stress conditions

Drought stress is one of the most important factors limiting the productivity of crop plants around the world. Genotype-by environment (G×E) interactions are common under drought and make breeding progress difficult. For this reason twenty genotypes of bread wheat were evaluated in a randomized complete block design with 3 replications at 2 locations (stress and non-stress environments) in two growing seasons. Stability of genotypes were evaluated by using of several methods such as coefficient of regression and deviation from regression in method of Eberhart and Russell, stability variance of Shukla, simultaneous selection for yield and stability, Rick ecovalance and ranking method. The object of this study was to compare the results of above methods and to introduce the simplest method for determining stable genotypes. In the most methods genotypes 9 and 12 selected as stable genotypes. Coefficients of correlation between different methods were calculated using Spearman's coefficient. Regard to strength significant correlation between mean yield and mean of ranks in ranking method, strength significant correlations between deviation from regression and most of used methods and its highly significant correlation with standard deviation in ranking method, it's concluded that the simple method of ranking was enough for determining stable genotypes.