comparison of some common bean (phaseolus vulgaris l.) genotypes for drought tolerance

drought stress, especially drought at terminal stages, plays an important role in reduction of yield in field crops such as common beans. 50 genotypes of common bean including 3 control genotypes (dehghan, bahman and naz) were used to evaluate and identify the tolerant genotypes. this experiment were performed in a randomized complete block design (rcbd) with three replications under two conditions (stress and non-stress) using stress indices. mp, gmp, harm and sti indices were introduced as the best indices for screening genotypes because of their high correlation with yield under stress and non-stress conditions. based on the results of principal components analysis, the first component, which explained 65.96 percent of data variations, was considered as a component of yield stability and drought tolerance, and the second component, which explained 31.53 percent of the data variation, introduced as component of sensitivity to stress. based on a biplot analysis, genotypes 1, 16, 18 and 49 were introduced as tolerant genotypes with high yield potential. cluster analysis based on mp, gmp, harm and sti indices and yield under stress and non-stress were classified genotypes in four clusters. drought tolerant genotypes were located in the first cluster and the most drought-sensitive genotypes with the largest gap were located in the fourth cluster.