PHYSIO-BIOCHEMICAL RESPONSES OF COTTON FOR WATER STRESS TOLERANCE

Cotton, the white gold is also known as the king of fiber crops and is the main raw material for textile industry. The productivity in our country is lower as nearly 65 percent of cotton is grown as rainfed which is characterized by uneven insufficient rainfall coupled with drought. In rainfed condition cotton crop frequently encounters stresses usually during reproductive phase that adversely affect growth, development and productivity. The results indicated that stress condition influence various morphological and physio- biochemical characters and also their relationship with yield. Important findings that cotton plant has several adaptive mechanisms for coping with limited moisture supply as evident from osmotic potential, accumulation of soluble osmotic constituents like sugars, amino acid, glycine betaine etc., a low transpiration rate, high stomatal conductance, deeper roots, higher CSI, a high ROS scavenging enzymes maintaining stability resulting into higher biomass or a minimal reduction in the same under stress and finally better yield. The information thus generated would be useful in breeding for drought tolerance and higher yield in limited moisture supply conditions.