Abstract: An investigation was carried out on the colonization percentage,spore density,relative abundance,occurrence frequency,and species richness of arbuscular mycorrhizal (AM) fungi on 4 species of Dipterocarpaceae trees grown both in natural forests in Yunnan and Hainan Provinces and in greenhouse pots.The results showed that all dipterocarp species were able to form AM,the colonization rates ranged from 30.6% to 45.3%,37% on average.Hopea hainanensis (Dipterocarpacea) seedlings without AM fungal colonization were cultivated in pots with soil collected from Dipterocarpacea rhizosphere,and harvested a year later.The colonization rate of the seedlings ranged from 10.6% to 20.3%,14.2% on average,indicating the significant effect of host plants on AM fungi frequency.The relative abundance of Glomu,Acaulospora and Gigaspora also varied with host plants.It was concluded that the dominant AM fungi in the rhizospheric soil of dipterocarp plants were Acculospora spp.and Glomus spp.Using the same species of Dipterocarpacea as host plants might promote the growth and development of AM fungi,and increase the AM diversity.

Key words: Eriocheir sinensis, Gut, Chitin, Digestive bacteria