Evaluation of drought tolerance indices for identification of drought tolerant and susceptible genotypes in wheat (Triticum aestivum L.)

This experiment was designed to identify the drought tolerant and susceptible genotypes in wheat genotypes collected from different wheat breeding centre of India. The experiment was conducted in alpha lattice design under stress and non-stress conditions to estimate the drought tolerance indices. Nine drought tolerance viz., Tolerance index (TOL), Mean productivity (MP), Harmonic mean (HM), Stress susceptibility index (SSI), Yield index (YI), Relative drought index (RDI), Grain yield per plant under potential condition (Yp ), Grain yield per plant under stress condition (Ys) were calculated. The indices were estimated based on grain yield under stress condition (Ys) and non-stress condition (Yp). These indices were subjected for analysis of variance, correlation coefficient analysis, cluster analysis. SSI is  suggested as useful indicator for wheat breeding where the stress is severe; while MP, TOL and HM are suggested if the stress is less severe. Based on grain yield per plant twenty-one tolerant genotypes and eleven susceptible genotypes were identified. Identified tolerant and susceptible genotypes can be used for the development of mapping populations to identify QTLs for drought tolerance in wheat (Triticum aestivum L.).