Munjal, RenuKirpa Ram2018-04-162018-04-162017http://krishikosh.egranth.ac.in/handle/1/5810043628The present investigation was conducted to assess the effects of drought and heat stress conditions on carbohydrate accumulation and partitioning and identify physiological and biochemical traits related to accumulation and partitioning of carbohydrate under drought and heat stress conditions. The eight wheat genotypes (AKAW-3717, DHTW-60, C-306, HD-2967, HTW-11, WH-730 and WH- 1105) in RBD with 4 rows of 2m length with a 20×5 cm spacing within rows and plants respectively, were grown during rabi season of 2015-16 and 2016-17 at Field Research Area, Wheat & Barley Section, Department of Genetics & Plant Breeding. Effect of individual drought and high temperature and their combination on physiological, biochemical and yield parameters under timely, late and very late sown condition was studied. Reduction in response of drought and high temperature was observed in physiological parameters (relative water content, osmotic potential, water potential, chlorophyll content, chlorophyll florescence taken in flag leaf) and biochemical parameters (peduncle and penultimate internode) at anthesis and 15 days after anthesis. Reduction in physiological and biochemical parameters was more pronounced under D40+D65 and complete drought at 15 days after anthesis as compare to anthesis. Metabolite (glucose, fructose, sucrose, water soluble carbohydrate and cellulose) and enzyme (SuSy, INV, SBE, SDBE and AGPase) activity get reduced under drought and with combination of delayed sowing. Fast rate of decline both in peduncle and penultimate inter node was observed. Yield was found highly associated with physiological and biochemical behavior of stressed plant. Yield penalty was more in combination of delayed sowing and drought situation at different growth stage. Genotype DHTW-60, HD-2967 and WH-1105 found promising in overall performance under timely, late and very late with different drought & high temperature situation. Carbohydrate metabolic & enzymatic traits with water relation & chlorophyll related traits are best traits for selection of drought and high temperature tolerant genotype.ennullThesis