关键词: 铅锌矿区，植物内生真菌，分离频率，遗传多样性

Abstract:

[Objective] To analyze the distribution characteristics and genetic diversity of plant endophytic fungi in Pb-Zn mine area. [Methods] Using the tissue cultivation method, endophytic fungi were isolated from six plant species collected from one Pb-Zn mine area in Hanyuan, Sichuan province. Based on their morphological characteristics, 27 endophytic fungal strains were selected and carried out the genetic diversity analysis by using RAPD fingerprinting technique, and then one representative strain from each genetic cluster according to the RAPD result was used for rDNA-ITS sequencing, by which phylogenetic tree was constructed using neighbor-joining method with MEGA 4.0 software. [Results] A total of 186 endophytic fungal strains were isolated from 300 tissue segments of the six different plant species. The isolation rate ranged from 0.43 to 0.85 with the mean rate of 0.62. Stem was found having the highest isolation rate in all six plant species, and leaf came second and root was the lowest. The RAPD analysis showed that 27 strains were genetically clustered into eight different groups at the level of 76 % similarity. Phylogenetic analysis based on the ITS sequences of representative strains of eight groups showed that these eight endophytic fungi were closely related to Fusarium, Penicillium, Dothideomycetes, Plectosphaerella, Myrothecium, Pleosporales, Alternaria and Pestalotiopsis, respectively. [Conclusion] The study suggested that plants in this Pb-Zn mine area had diverse endophytic fungi to some extent. However, the ecological function of them in such extreme environment is still not clear, which is worthy to be studied further.

Key words: Pb-Zn mine area, endophytic fungi, isolation rate, genetic diversity