Biochemical investigation of Triticum aestivum L. genotypes under different growth stages exposed to terminal heat stress

Abstract

In the present study, the effect of terminal heat stress on 10 wheat genotypes (viz., VL-832, HD-3065, WH-1124, WH-1100, VL-892, Halna, PBW-590, PBW-658, PCPGR- 7854, and DBW-90) was evaluated under timely and late sown conditions. Various Physio-biochemical parameters were ascertained in all the cultivars throughout the growth duration stages. Increasing temperature showed marked effect in various physiological and biochemical parameters tested in all genotypes under study. The genotypes differed significantly with respect to time of sowing (timely and late) having significant effect on plant height, LAI and Fv/Fm ratio. Decrease in H2O2 content was observed in PBW-590, PBW-658, PCPGR-7854, Halna and WH-1124 under terminal heat stress (showing their better tolerance). Lower level of MDA was observed in WH-1124, VL-832 and PCPGR-7854. Elevated CAT activity was observed in WH-1124, PBW-590, Halna and PCPGR-7854 under terminal heat stress. APX activity increased significantly in DBW-90, HD-3065 and PBW-590 whereas POD activity increased significantly in PBW-658, WH-1124 and WH-1100 under terminal heat stress. The present study revealed that terminal heat stress causes significant oxidative damage by production of reactive oxygen species, causing membrane damage via, lipid peroxidation and triggers the production of antioxidant enzymes in tolerant genotypes