Abstract:Tall fescue species "Arid Ⅲ" and arbuscular mycorrhizal fungus Funneliformis mosseae and Rhizophagus intraradices were used as materials in this experiment, the soil campaction (1.2 g·cm-3、1.3 g·cm-3、1.4 g·cm-3、1.5 g·cm-3 treatment) and inoculation with AMF [inoculation with F. mosseae, R. intraradices, F. mosseae +R. intraradices and non-inoculation treatment] were tested in two factors under greenhouse conditions, to evaluate the effect of AMF on physiology and ecology of tall fescue. The results showed that, under 1.5 g·cm-3 soil compaction stress (1) AMF could effectively increase the plant height, tiller number, dry matter quality, the activity of root system, catalase, the chlorophyll a and b, chlorophyll content, net photosynthesis rate (Pn), transpiration rate (Tr), stomatal conductance (Gs) and reduce the intercellular CO2 concentration (Ci) in leaves of tall fescue. (2) Double inoculation treatment resulted in the increase of colonization and hyphal density, reaching 17.3% and 25.2% respectively as compared with F. mosseae, compared with R. intraradices, double inoculation treatment were increased 53.0%, 36.3%. And, double inoculation with F. mosseae+R. intraradices treatment resulted in the increase of plant height, tiller number, dry matter quality, the chlorophyll a and b, chlorophyll content, Pn, Tr and Gs of leaves of tall fescue with double inoculation treatment reaching 36.1%, 39.5%, 114.0%, 43.1% , 100.0%, 59.3%, 52.5%、33.3%、181.1% , while their Ci decreased by 32.9%, respectively, as compared with the uninoculated control; the activity of root systemand catalaseIn addition was 1.4 times and 1.5 times higher than that in the control, respectively. It can be seen that AMF can enhance the ability of tall fescue under campaction tolerance by enhancing the activity of root system, reducing the damage caused by oxidative stress, regulating chlorophyll content and photosynthesis in plants, and the effect of double inoculation with F. mosseae+R. intraradices is better than that of single inoculation.