Effects of endophytic fungi on perennial ryegrass physiological characteristics under different growth conditions

In order to explain endophytic fungi affects internal physiological mechanisms of perennial ryegrass under different growth conditions. This study compared the physiological changes of infected endophytic fungi (E+), free endophytic fungi (E-) and mixed (M) three ryegrass (Lolium perenne) populations under natural field conditions and greenhouse with different water treatments.The results showed that endophyte significantly (P0.05) increased the total chlorophyll content, soluble sugar content, proline acid content, superoxide dismutase activity and catalase activity of ryegrass, but the malondialdehyde content and peroxidase activity were reduced when the water content was 15% FWC (drought) and 60% FWC(flood) of the soil saturated water content under greenhouse conditions; These three populations had no significant difference in physiological parameters at 45% FWC soil moisture content; This showed that the endophytic fungi increased the resistance of the host by improving the protection of enzyme activity under stress conditions. Under natural field conditions, the changes trend of chlorophyll content, soluble sugar content, proline content, superoxide dismutase activity and catalase activity in ryegrass showed that E+ M E-, malondialdehyde content and peroxidase activity showed that E- M E+. In conclusion, endophyte also can promote the growth of hosts by changing the internal physiological mechanisms under natural growth conditions.