Physiology of Cell Membranes, Stomata And Photosynthetic Pigments of Rice (Oryza Sativa L.) Under High Temperature.

Twenty genotypes of rice were evaluated for their physiological tolerance of cellular membrane, stomata and photosynthetic pigments under high temperature stress. The selected genotypes were grown at two sowing dates viz; normal and stress environment. High temperature negatively affected these parameters and genotypic variation was observed. Photosynthetic pigments were significantly reduced under stress, while the number of stomata increased. Membrane thermal stability (MTS) decreased with increasing temperature exposure; hence 30 o C recorded highest while 55 o C recorded lowest MTS. Genotype Ganjay had highest chlorophyll a with lowest number of stomata in lower epidermis under stress. The highest MTS values were recorded for genotypes PR121, IR6 and PR122. These four genotypes can be recommended for growing under high temperature stress.