Sandooja, J.K.Biswabiplab Singh2018-02-242018-02-242017http://krishikosh.egranth.ac.in/handle/1/5810041334The present study was conducted in earthen pots containing 5kg dune sand, to evaluate physiological, biochemical and yield related attributes under PEG induced water stress and the adaptive responses of SNP in three cotton hybrids namely BG 6488 II, HHH-223 and AAH-1 under controlled screen house conditions. Plants were supplied with nutrient solution at regular intervals. PEG 20%, 40% and 60% water stress was induced after 60 days of sowing at reproductive stage. NO was applied in the form of SNP (250μM) in all the stressed and control plants. Observations were recorded on 3rd, 6th and 9th days after all the treatments were given. A significant decreasing trend in physiological parameters like total chlorophyll content, chlorophyll fluorescence, relative water content, photosynthetic and transpiration rate was clearly observed with 20%, 40% and 60% PEG induced water stress. Exogenous application of SNP through foliar spray was very much effective and increased the values of these parameters significantly in 20% PEG+SNP and 40% PEG+SNP but ineffective in 60% PEG treated plants. The cotton hybrid BG 6488 II performed relatively better with respect these parameters as compared to others. Due to the water stress, the H2O2 content, lipid peroxidation level and membrane injury % increased significantly from the control plants and maximum values were recorded in 60% PEG treated plants. SNP application was effective and decreased the values of these parameters significantly in 20% and 40% PEG treated plants but SNP was ineffective with 60% PEG. There were significant accumulation of osmolytes such as total soluble sugars, proline and total soluble proteins under PEG induced water stress and further increased in combination with 20% PEG+SNP and 40% PEG+SNP but ineffective with 60% PEG+SNP treatment. Yield and yield related attributes also significantly decreased by PEG water stress and SNP was found to mitigate the yield losses. The cotton hybrid BG 6488 II was found to perform relatively better as compared to others with respect to these physiological, biochemical and yield attributes studied.ennullThesis