Effect of Epichloë gansuensis on arbuscular mycorrhizal fungi spore diversity in rhizosphere soil of drunken horse grass under different growth conditions

The present study was conducted to measure the colonisation rate of arbuscular mycorrhizal fungi (AMF), soil spore density, and AMF diversity under different growth conditions, based on root staining and morphological identification of spores. The results indicated that AMF colonisation rate of cultivated roots were significantly higher than that in wild roots (P<0.05) under cultivated conditions, and that endophytes significantly increased the AMF colonisation rate (P<0.05). Spore density in wild soil was significantly higher than that in cultivated soil (P<0.05). Under cultivated conditions, endophytes significantly enhanced the spore density (P<0.05). Under cultivated conditions, three genera and nine AMF species were detected, including seven Glomus, one Gigaspora, and one Scutellospora species. Endophyte-infected roots (E+) contained six Glomus and one Gigaspora species; endophyte-free roots (E-) contained three Glomus, one Gigaspora, and one Scutellospora species. Two genera, including nine AMF species (eight Glomus and one Gigaspora species) were found under wild conditions. Glomus was the most abundant AMF species. The AMF species richness of wild soil was significantly higher (P<0.05) than that under cultivated conditions. However, endophytes had no significant effect (P>0.05) on AMF species richness. These results demonstrated that endophyte infection and growth conditions might change AMF community structure.