Isolation, Identification And Diversity Anaiysis Of Phododendron Plants Mycorrhizal Fungi

Rhododendron is a world-renowned ornamental plant and one of the top ten traditional famous flowers of China. China has abundant Rhododendron resources which is an important birthplace and distribution centers. Fungi and Rhododendron plants form a symbiotic relationship. Ericoid mycorrhizal fungi can promote the absorption of nutrients, enhance plant vigor, improve soil and enhance plant resistance to pests and diseases such as the roles. The domestic research work started late. There are rare-related reports. This research has isolated mycorrhizal fungi from several representative areas of rhododendron plants, identified some fungi by traditional classification method of morphology. Ericoid mycorrhizal fungi were identified by means of molecular biology. This research preliminarily studied the diversity of Ericoid mycorrhizal fungi.The results are as follows:1 500 Ericoid endophytic fungal strains divided into 24 species have been isolated from 24 Rhododendron plants of different distributions and species.2 Selection-tests for optimum conditions of mycorrhiza fungi isolation showed that, using appropriate disinfection methods and time, Selecting the roots with 0.5-1.0mm in diameter can obtain better isolation results.3 Morphological combined rDNA ITS sequence analysis identified four kinds ericoid mycorrhizal fungi:Phialocephala fortinii,Oidiodendron maius,Meliniomyces variabilis,Cryptosporiopsis ericae and two epacrid root endophyte homologous or closely related species. The results of two methods indicate the ITS technology in the study of ericoid mycorrhizal fungi reveals better practicability.4 Ericoid mycorrhizal fungi isolated from Changbai Mountain in Ji Lin, Jin fo Mountain in Chongqing and Dali Yunnan were analyzed by rDNA internal transcribed spacer (rDNA ITS) sequences, initially reveal the inherent law of the diversity of ericoid mycorrhizal fungi.In the same area, Ericoid mycorrhizal fungi have rich diversity, the majority of ericoid mycorrhizal fungi have consistency between different regions. Strains in different regions also showed significant divergences:The dominant strain of Changbai Mountain is Phialocephala fortinii; Cryptosporiopsis ericae is dominant strain in Jinfo Mountain.5 Rhododendron hippophaeoides was studied by Denaturing Gradient Gel Electrophoresis (DGGE).Hymenoscyphus ericae is isolated.