High temperature induced biochemical changes in pearl millet genotypes at seedling stage

Thirteen genotypes of Pearl millet (Pennisetum glaucum (L.) R. Br.) selected on the basis of heat tolerance were studied to see changes at biochemical and physiological levels. The plants were initially raised under normal condition in small plastic pots and 20 days old seedling were exposed at (40 °C for 4 hrs, 44 °C for 4 hrs and 46 °C for 2 hrs) in BOD incubator at Mandor to create the heat stress condition. After two days treatment data were recorded for MSI, chlorophyll content, antioxidative enzymes and MDA content. MSI, chlorophyll content and MDA decreased significantly due to heat stress while SOD, and CAT increased significantly under heat stress condition. The genotypic difference was also found significant. In some genotypes R/S increased while in some genotypes R/S ratio decreased under heat stress. The genotypes and PPMI 1053 and PPMI 1087 and HB 17-6 perform better having antioxidative enzymes. The better performance of these genotypes may be due to high RWC, MSI, chlorophyll, SOD, CAT and low MDA content under high temperature stress.