Locating QTLs controlling yield based indicators of drought tolerance in agropyron using wheat-agropyron disomic addition lines

ABSTRACT: This study was conducted to locate the genes monitoring drought tolerance criteria in Agropyron elongatum using wheat-agropyron disomic addition lines under drought stress condition. The plant genetic materials were tested in a completely randomized block design with three replications under two different water regimes (irrigated and rainfed). 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 stress (Ys) and irrigated conditions (Yp). The results of analysis of variance exhibited significant differences between grain yield in stress and non stress conditions (Yp and Ys ) at 1% probability level. Comparison of means showed that the disomic addition line 4E had the highest grain yield in stress condition and 1E had the highest grain yield in non stress condition indicating that chromosomes 4E and 1E carrying QTLs controlling Ys and Yp, respectively. The highest amount of STI, GMP, HM and YI was attributed to addition lines 4E and 5E, therefore QTLs monitoring yield based drought tolerance indicators are located on chromosomes 4E and 5E and hence they can be used for improvement of drought tolerance in wheat through chromosome engineering.