Effects of endophytic fungi on seed germination of perennial ryegrass under salt stress

To evaluate the effect of salinity and endophytic fungi on seed germination of Lolium perenne, 8 perennial ryegrass varieties with high endophyte infection rate (80%) and 8 varieties with low rate (20%) were used for germination experiment under salinity stress. The results of this study showed that the relative germination rate (RGR), relative vitality index (RVI), relative root length (RRL), relative shoot length (RSL) and relative root/shoot ratio (RRS) decreased with increasing NaCl concentrations. There was no significant difference observed in RGR, RVI, RRL and RSL between high and low infection rate under 0, 85, and 170 mmolL-1 NaCl stress, while RGR, RVI, and RSL of seeds with high infection rate were significantly (P0.05) higher than that of low infection rate under 255 mmolL-1 NaCl stress. In a word, seed germination of perennial ryegrass was inhibited by salt stress, but endophyte infection could benefit seed germination under high salinity condition.