Effect of endophytic fungi from Dioscorea opposite Thunb. on growth promotion of Ruichang yam

To explore the promoting effect of endophyte fungi on the host plant, 4 IAA -producing strains (strain numbers: YS07, YS16, YS21, YS27)were obtained from 48 strains endophytic fungi of Dioscorea opposite Thunb. by Salkowski colorimetric. Aseptic seedlings of Ruichang yam and endophytic fungi were cultured together, and the growth of the seedlings and the endophytic fungi colonization in roots were observed. The results showed that the seedlings of Ruichang yam had significant increases in the fresh weight of plants, number of roots, root-shoot ratio and amount of chlorophyll which cultured with endophytic fungi. There were differences in IAA-producing and promoting effect among the endophytic fungi, the order of promoting effect of 4 strains was YS27>YS21>YS07>YS16