The Effects Of Salicylic Acid(SA) On Drought Resistance Of Tall Fescue (Festuca Arundinacea)

Tall fescue is widely cultivated in cool arear as a kind of cool-season turfgrass, however, drought stress is one of factors which limits tall fescue widely applied in arid and semi arid areas. It is always fail to plant turf and increases maintenance and management costs in these areas because of drought stress, Therefore, to study how to improve turfgrass drought resistance is necessary. In this experiment, Tall fescue(Festuca arundinacea) seeds (Bonsai 2000, Houndogâ…¤, Ruby) was soaked in different concentrations of salicylic acid (SA)(0-3.00mmol/L) to study SA on the simulation of tall fescue seed germination under drought stress; with different concentration of SA (0-3.00mmol/L) sprayed on leaves, effects of SA on root and some physiological characteristics of tall fescue under the continuous drought stress were studied. So the objectives of this study were to find appropriate SA concentrations which could improve the drought resistance of tall fescue through this experiment, and to provide theoretical reference for practical application of SA which used in plant and maintain tall fescue turf. The results show that:the appropriate SA concentrations can promote tall fescue seeds germination and improve tall fescue drought resistance in the continuous drought stress. The main conclusions are as follows:1,SA soaking seeds of tall fescue at the appropriate lower concentrations(0.25-1.00mmol/L) could increase germination potential, germination rate of Tall Fescue seeds, promote the growth of the seedling and root and could improve the drought resistance of Tall Fescue at seed germination period under PEG simulated drought stress. However, the higher concentrations inhibited germination and growth of the seeds,3.00mmol/L displayed significant inhibiting effect(P<0.05). Among these different concentrations, the 0.5mmol/L SA showed the best one.2,Under the continuous drought stess, spraying appropriate concentrations SA on tall fescue' leaves could promote the growth of root, raise leaf relative water content and leaf water potential, reduce the relative conductivity rate and accumulation of MDA, increase osmoticum Pro content, increase chlorophyll content of leaves, raise net photosynthetic rate, lower stomatal conductance and transpiration rate. All indices above show that appropriate concentrations SA sprayed on leaves could improve the drought resistance of tall fescue. Higher concentrations of SA treatments on tall fescue' drought resistance results were not very good, even exacerbated inhibition. Among them,0.24mmol/L-0.50mmol/L SA treatments showed the best, could significantly improve the drought resistance of tall fescue (P<0.05).