Anti-oxidative response of different wheat genotypes to drought during anthesis .

The aim of this work was to study drought effects on lipid peroxidation, antioxidant compounds, and anti-oxidative enzymes activities in two tolerant (Daric and 92 Zhong), two moderately tolerant (Sabalan and DH-2049-3) and two sensitive (Shark and Tevees) wheat genotypes. Malondialdehyde content and electrolyte leakage increased significantly (P<0.05) in flag leaves under drought. The increase was higher in sensitive genotypes compared to the others. Protective enzymes activities (ascorbate peroxidase, peroxidase, superoxide dismutase, catalase and glutathione reductase) and non- enzymatic antioxidants contents (ascorbate and glutathione) increased under drought stress and this increase was higher in tolerant genotypes. There were significant positive correlations (P<0.05) between anti-oxidative enzyme activities and non- enzymatic antioxidants. It seems that peroxidase and superoxide dismutase - that showed higher increase under stress- had an important role in drought tolerance.