Effect of Drought Pre- conditioning on Antioxidant enzymes activity and reducing drought stress damage in two turfgrass species, creeping bentgrass and tall fescue

Drought preconditioning، which is irrigation with low frequency and longer duration، could be used for extending root system and suppressing drought damage in plants. In the present study، the effect of drought preconditioning for 30 days on increasing tolerance to drought stress in two turfgrass species، creeping bentgrass (Agrostis stolonifera cv. Palustris) and tall fescue (Festuca arundinacea cv. Greystone) was investigated. Drought preconditioning and control plants were irrigated for 50 days with different levels of soil suction (20-23،40-43، 50-53 and 70-73 centibar)، and finally، plants were watered up to field capacity point for 15 days، in order to recovery. The results showed that drought preconditioning increased root to shoot length ratio in both grass species. Preconditioning in both species also showed the higher leaf peroxidase، superoxide dismutase، ascorbat peroxidase and catalase activity than control plants at the end of 50 days of drought stress treatments. At recovery stage، activity of antioxidant enzymes was higher only in preconditioned creeping bent grass compared to control plants. Overall، drought preconditioning could increase drought stress tolerance in both turfgrass species by increasing root to shoot ratio and improving enzymatic antioxidant systems.