Application of integrated selection index and rank sum for screening drought tolerant genotypes in bread wheat

v: In order to screen bread wheat drought tolerant genotypes using agronomic and physiological criteria, thirty bread wheat genotypes were assessed under post anthesis drought stress (rainfed) and irrigated conditions. The Experiment was conducted in a randomized complete block design (RCBD) with three replications under two different rainfed and irrigated conditions during the growing season 2010-2011. Principal component analysis (PCA) showed that integrated selection index (ISI) was correlated with relative water content (RWC), relative chlorophyll content (RCC), stress yield (Ys) and yield potential (Yp) indicating that ISI was able to distinguish group A genotypes (drought tolerant with high grain yield under rainfed and irrigated conditions). Screening drought tolerant genotypes using mean rank, standard deviation of ranks and rank sum (RS), discriminated genotypes WC-4958 (9), WC-4592 (4) and WC-4612 (16) as the most drought tolerant. Therefore, they are recommended to be used as parents for genetic analysis, gene mapping and improvement of drought tolerance in common wheat.