Evaluation of Wheat Genotypes (Triticum aestivum L.) against Heat Stress based on Their Biochemical and Physiological Responses

The experiment was carried out using fourteen wheat genotypes differing in susceptibility to temperature stress and heat treatment was given to 10 days old wheat seedlings at 35°C, 40°C and 45°C for four hour in seed germinator. Relative water content and membrane stability was highest in tolerant genotype GW-190 and was the lowest in susceptible genotype J-2010-11. Membrane injuries, lipid peroxidation and hydrogen peroxide content were highest in susceptible genotype J-2010-11 and were the lowest in tolerant genotype GW-190. Chlorophyll stability index was highest in susceptible genotype LOK-1 and the lowest in tolerant genotype GW-190. In general as the temperature stress increased relative water content and membrane stability decreased and membrane injury, hydrogen peroxide and lipid peroxidation increased in all the genotypes compared to control plants.