WHEAT (TRITICUM AESTIVUM L.) DROUGHT TOLERANCE INDICES UNDER WATER STRESS CONDITIONS

Ten wheat varieties, Benazir, Hamal Fakir, TD -I, NIA Sunder, TJ-83, Marvi-2000, NIA Amber, Sarsabz, Kiran-95, and Imdad-05, sown in split -plot design (SPD) with three replications, underwent wellwatered and water -stress influences at the time of anthesis, at the Botanical Garden, Department of Plant Breeding and Genetics, Sindh Agriculture University, Tandojam, during 2022-2023. The observed traits included days to 1st booting, days to 90% heading, days to 90% maturity, peduncle length (cm), plant height (cm), tillers plant -1, spike length (cm), spikelets spike -1, grains spike -1, seed index (1000 -grain weight, g), grain yield plant -1 (g), biological yield plant -1 (g), and harvest index (%). Based on drought tolerance indices, the result demonstrated that genotypes, treatments, and genotypes xtreatments significantly affected yield and its contributing traits. The genotypes, such as Imdad-05, NIA Amber, and TD -1, considerably exhibited drought tolerance, whereas Marvi-2000 and Kiran-95 were susceptible. The grain yield expressed positive and significant association toward other traits, such as days to 1st booting, days to 90% heading, days to 90% maturity, peduncle length, plant height, tillers plant -1, spike length, spikelets spike -1, grains spike -1, seed index grain weight, grain yield plant -1, biological yield plant -1, and harvest index. Seven indices calculated grain yield in Yp and Ys appeared significantly and positively associated with the first three components mentioned at about 95.76% of the total variability and directly connected with the STI, GMP, TOL, and MP, namely, Imdad-05, NIA Sunder, and TD -1 considered as highly drought -tolerant; Marvi-2000 and Benazir, as moderately tolerant, and NIA Amber and Kiran-95 were the susceptible ones.