| With the rapid development of social economy, urban environmental protection, water and soil conservation, highway slope protection projects put forward a higher and more pressing demand in lawn business, the construction of sports and rest concourse also put forward a growing demand in lawn. But the construction of lawn has much difficulty due to environmental restrictions, such as the salinization and basification of soil which is one of the natural adversities during the virescence process. Therefore, the research of turf-grass salt resistant mechanism is an important topic. Tall fescue as an excellent cold-season type turf-grass is one of the most common used cold-season type turf-grass which was widely used in constructing lawn.The effect of physiological metabolism of tall fescue under salt stress and Exterior Ascorbic acid (ExAsA) mitigation effect on salt stress in tall fescue was researched in order to improve the salt tolerance of turf-grass. That will provide theoretical basis and technical support for the mitigation damage of salt stress in turf-grass. The main results as follows:1. The biomass and the content of MDA was not affected significantly when tall fescue were stressed by50, lOOmmol/L of NaCl in comparison with the control, and obvious descend in growth as well as obvious ascend in the MDA content by200,300mmol/L of NaCl. The activities of antioxidant enzymes increased at the early days, and decreased with prolonging duration of NaCl treatment, and decreased the most at the highest concentration. The content of the three antioxidant decreased gradually except for caroteniod increased at the early days, and decreased with prolonging duration of NaCl treatment, and decreased much more obviously at the200,300mmol/L concentration.2. The experiment was conducted to study the concentration and spraying frequency effect of ascorbic acid on the growth physiological condition of tall fescue under salt-stress. The results showed that ascorbic acid improved the antioxidant enzymes activity and improved the ASA and GSH content, reduced the MDA production. It improved the chlorophyll and caroteniod contents, and also improved the lawn salt resistance. The suitable treatment was20mmol/L spraying concentration once every week.3Under salt stress, the antioxidant enzymes activit(SOD and CAT) and the antioxidant content enhanced obviously after AsA was added, POD was droped obviously, when the concentration of AsA was O.lmmol/L, witch was favorable for growth, The AsA solution at low concentration could relieve the inhibitory effect of salt stress on the seed germination and seedling growth of tall fescue and the effect of AsA solution at high concentration was not obvious. |
