PHYSIOLOGICAL RESPONSES AND DROUGHT RESISTANCE INDEX OF NINE WHEAT (TRITICUM AESTIVUM L.) CULTIVARS UNDER DIFFERENT MOISTURE CONDITIONS

Nine commercial wheat cultivars of Pakistan viz; Inqulab-91, AS-2002, Sehar-2006, Shafaq-2006, Bhakkar-2002, Auqab-2000, GA-2002, Chakwal-50 and Fareed-06 were evaluated for their physiological performance and drought resistance index under different levels of soil moisture. Germination of these cultivars was tested under PEG induced osmotic stress of -2, -4, -6, and -8 bars. Highest germination percentage was observed for Fareed-06, Chakwal-50, GA-2002 and AS-2002 at -8 bars osmotic stress. To study physiological responses and drought resistance index, plants were grown in clay pots and water equivalent to 75%, 50% and 25% field capacity was applied. Decrease in soil moisture significantly affected relative water content, leaf succulence, chlorophyll content, cell membrane stability index, number of grains/spike and 100 grain weight. Significant variation was found among cultivars. Based on physiological responses and drought resistance index performance of Chakwal-50, GA-2002 and Bhakkar-2002 were found relatively better under limited moisture conditions.