Screening quantitative indicators of drought tolera nce in bread wheat (Triticum aestivum L.) landraces

Abstract

In order to study the response of twenty different bread wheat (T. aestivum L.) landraces to drought san experiment was conducted in a randomized complete b lock design with three replications under rainfed a nd irrigated conditions during 2010-2011 cropping seas on. Significant positive correlation was found betw een grain yield in the stress condition (Ys) with indices stress tolerance index (STI), geometric mean productiv ity (GMP), mean productivity (MP), yield index (YI), yield sta bility index (YSI), drought response index (DRI), d rought resistance index (DI), relative drought index (RDI) , abiotic tolerance index (ATI), stress non-stress production index (SNPI) and modified stress tolerance index (MSTI). Significant negative correlation was found between Ys with RDY and SSI indices. Principal component analysis (PCA) , indicated that first and second PCA accounted for 98.87% of variations among the indices. Biplot diagram indic ated that the most suitable indices for screening d rought tolerant genotypes were GMP, MP, STI, K 1STI, K 2STI, YI, DRI, DI, SNPI, RDI and YSI. Screening drou ght tolerant genotypes using ranking method discriminated genoty pes (18), (10), (2) and (5) as the most drought tol erant. Therefore they are recommended to be used as parent s for genetic analysis, gene mapping and improvemen t of drought tolerance in common wheat.