Assessment of drought tolerance indices for screening of rainfed wheat genotypes

In order to determine the most desirable index and to identify drought resistant genotypes, twenty five rainfed wheat genotypes were evaluated in randomized complete block design with three replication under three separate experiments (rainfed, post anthesis moisture stress and irrigated conditions). Analysis of variance showed significant differences for all characters, especially for grain yield performance. Indices of drought tolerance were calculated based on the yield under three environments in two cases. Principal component analysis in both cases reduced five indices down two components. Correlation analysis among grain yield in three environments, indices and also biplot analysis, revealed that geometric mean productivity (GMP), mean productivity (MP) and stress tolerance index (SIT) are the superior criteria for selection of high yielding genotypes. Kohdasht, Nestor and Maroon genotypes with less grain yield fluctuation in three conditions were introduced as drought tolerant genotypes.