关键词: 兰属植物, 菌根真菌, rDNA ITS分析, 瘤菌根菌, 胶膜菌属

Abstract: rDNA internal transcribed spacer analysis (rDNA ITS) was used to study diversity of 12 representative mycorrhizal Rhizoctonia strains, which were isolated from Chinese orchids (Cymbidium) distributed in different sites and belonged to different ecologic types. The Blast results indicated that all these strains belonged to Epulorhiza or Tulasnella, which was fully consistent with identification as Epulorhiza with morphological method. Additionally, based on rDNA ITS sequence cluster analysis, dendrogram of Cymbidium mycorrhizal strains showed that the distributed environments and orchids species were two crucial factors that affected the specificityrelation between Chinese orchids (Cymbidium) symbiotic mycorrhizae and hosts.

Key words: Cymbidium, mycorrhizalfungi, rDNA internal transcribed spacer analysis, Epulorhiza, Tulasnella