An Identification of Drought Tolerant Genotypes in Wheat using Analysis of Drought Resistance Indices

In order to identify drought tolerant varieties using drought tolerance indices، 24 genotypes of wheat were planted in a randomized complete block design with three replications under rainfed and irrigated conditions at the Research field of Agriculture faculty، Islamic Azad University of Sanandaj. Drought tolerance indices including mean productivity (MP)، tolerance index (TOL)، geometric mean productivity (GMP)، stress susceptibility index (SSI) and stress tolerance index (STI) were calculated on the basis of grain yield per plant under irrigated (Yp) and rainfed (Ys) conditions. Highly significant differences were observed among genotypes for all indices، potential and stress grain yield that indicated the present of genetic variation. It’s possible selection among genotypes for drought tolerance، hybridization for the genetic studies and breeding programs. Correlation analysis between grain yield per plant in the rainfed and irrigated conditions with drought tolerance indices showed the MP، GMP and STI indices are suitable for screening wheat genotypes. Regarding these criteria and high grain yield in both of two conditions Quds، Azar2، Kavir، Chamran and Mahdavi were diagnosed drought tolerant genotypes. Gabriel Biplot Multivariate chart showed Quds، Azar2، Kavir، Chamran and Mahdavi genotypes were located near to the vectors of drought tolerance indices، MP، GMP and STI. Finally، Azar2، Quds and Kavir genotypes were introduced as the most tolerant genotypes because they produced the highest performance in rainfed condition. The distribution of genotypes in Gabriel Biplot space showed the genetic variation among genotypes to drought stress.