Effective selection criteria for screening drought tolerant landraces of bread wheat (Triticum aestivum L.)

摘要

In order to evaluate the ability of several selection criteria to identify drought tolerant landraces of bread wheat 20 landraces were evaluated in a randomized complete block design with three replications under irrigated and rainfed conditions. Fourteen drought tolerance indices including stress tolerance index (STI), geometric mean productivity (GMP), mean productivity index (MP), stress susceptibility index (SSI), tolerance index (TOL), yield index (YI), yield stability index (YSI), drought response index (DRI), drought resistance index (DI), modified stress tolerance index (MSTI), relative drought index (RDI), abiotic tolerance index (ATI), stress susceptibility percentage index (SSPI) and stress non-stress production index (SNPI) were calculated and adjusted based on grain yield under drought (Ys) and irrigated conditions (Yp). Significant positive correlation was found between grain yield in the stress condition (Ys) with criteria STI, GMP, MP, YI, YSI, DI, K1STI, K2STI, RDI, SNPI, SSI and DRI indicating that these indices discriminate drought tolerant genotypes in the same manner. Principal component analysis (PCA), exhibited that first and second PCA accounted for 99.02% of the variation. Screening drought tolerant genotypes using mean rank, standard deviation of ranks and biplot analysis, discriminated genotypes (15), (3) and (6) 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.