study of terminal drought tolerance in promising barley genotypes using stress susceptibility and tolerance indices

abstract: evaluation of drought tolerance for 20 barley genotypes were conducted under normal irrigation and terminal stress condition by withholding irrigation at the time of 50% flowering. drought effect on grain yield and plant total mass traits was studied and eight of stress indices including stress tolerance index (sti), stress tolerance (tol), stress susceptibility index (ssi), mean productivity (mp), geometric mean productivity (gmp), yield index (yi), yield stability index (ysi), harmonic mean (harm) were estimated based on grain yield under stress (ys) and non-stress (yp). a significant and positive correlation was observed between grain yield and total mass (stress and potential) with gmp, harm, mp, yi and sti. stress indices such as gmp, sti, harm, yi and mp are much better than ysi, ssi and tol for predicting yp and ys. by using ranking method for yield and total mass traits genotype numbers of two and five were categorized as tolerant, however line number one was detected as sensitive genotype. these genotypes can be used in crop development and breeding programs. genotype numbers eight and nine had the highest yield and total mass and consequently highest economic yield in both stress and non-stress condition that can be introduce for cultivation in varamin land.