urvey of antioxidant defensive responses in three genotypes of Lolium pernne under drought stress

The present study was aimed to investigate the effect of drought stress on antioxidant defensive responses of three genotypes of Lolium perenne. This investigation was performed as factorial and a randomized complete design with three replications under field conditions. The results indicated that drought stress significantly decreased the relative water content (RWC), fresh and dry weight, chlorophyll a, chlorophyll b and carotenoid contents, while the concentration of H2O2 and proline increased. Also, compared to the control, the activities of catalase (CAT), ascorbate peroxidase (APX), guaiacol peroxidase (GPX) and superoxide dismutase (SOD) increased due to drought stress. Regarding results of the relative water content, the activity of antioxidant enzymes and proline content, it is concluded that genotype 1 had more tolerance to drought compared to the two other genotypes.