MANISH KUMAR SINGH
Objective: Plants experience high temperature in many different ways, and adaptation or acclimation to high temperature occurs over different levels of plant organization. Keep this in mind the present work was undertaken to study the effect of high-temperature stress on antioxidant enzymes in chickpea genotypes Material Used Four chickpea genotypes differing in their sensitivity to high-temperature stress were taken and grown in growth chambers in the phytotron facility of IARI, New Delhi. The plants were maintained at 18/23°C (control) and 25/35°C (temperature stress) night/day temperature after maximum tillering. Results: In all chickpea genotypes high-temperature stress increased membrane injury index (MII), the activity of superoxide dismutase (SOD) and ascorbate peroxidase (APX), malic acid and slightly decreased the activity of glutathione reductase (GR), relative water content (RWC), chlorophyll and carotenoid contents. Under the HT stress, the tolerant genotypes Pusa-1103 and BGD-72 exhibited higher RWC, chlorophyll and carotenoid, the activity of SOD, APX, GR and, and less decrease in MII as compared to susceptible genotypes Pusa-256 and RSG-991. Antioxidant enzymes showed a positive correlation (r) with chlorophyll content, RWC and negative with MII under high-temperature stress. Conclusion: From the results, it is apparent that the antioxidant defense mechanism plays an important role in heat stress tolerance in chickpea genotypes and thus screening of tolerant genotypes by antioxidants enzymes, would be helpful in a further breeding programme of Chickpea.