伊犁退化野果林表土层土壤可培养真菌多样性

Diversity of Cultivable Fungi in Topsoil in the Degenerated Wild Fruit Forests in Ili

为认识伊犁退化野果林下表层土壤中可培养真菌的多样性,采用稀释平板法从野果林健康果树覆盖区表层土壤（H土）和患病果树覆盖区表层土壤（D土）中分离不同种类的土壤可培养真菌,基于可培养真菌ITS基因序列与NCBI数据库Gen Bank中的序列进行比对,选择相似性最高的参考菌株序列,并构建系统发育树。结果从退化野果林表层土壤中分离获得25株真菌菌株,隶属3亚门6纲8目11科11属。从H土分离的土壤真菌优势属为青霉属（Penicillium）,D土的土壤优势属为青霉属（Penicillium）和镰刀菌属（Fusarium）;聚孢霉属（Clonostachys）和拟青霉属（Purpureocillium）仅存于H土,茎点霉属（Phoma）和小球腔菌属（Leptosphaeria）仅存在于D土。H土可培养真菌Shannon-Wiener多样性指数（2.10）大于D土（1.98）,H土均匀度指数（0.91）亦高于D土（0.79）。由此可见,充分认识野果林真菌类群的分布有助于指导果林病虫害防治工作。

The wild fruit forests in the Tianshan Mountains,Xinjiang are one of the areas where deciduous fruit trees are originally cultivated in the world,they have the large area and are the most primitive,densest and relatively rare in Eurasia. In recent years,the wild fruit forest ecosystems have been seriously damaged due to the large-scale human development,and the species diversity was decreased. Current research on wild fruit ecosystem focuses mainly on the aboveground biomass and its related aspects,but the microbial change in groundwater is paid little attention to. The objective of this study was to evaluate the diversity of cultivable fungi isolated from topsoil under health fruit trees（ H soil） and diseased fruit trees（ D soil） in a degenerated wild fruit forest. Dilution plate technique and 18 s r DNA sequence analysis were applied to obtain the sequences of 25 difference strains isolated from the degenerated wild fruit forest,which were subsequently submitted to Gen Bank and compared with the known sequences to build up a phylogenetic tree. Results revealed that：（1） These strains were clustered into 3 subdivisions,6 classes,8 orders,11 families and 11 genera;（2） The dominant genera of the H soil was Penicillium,while Penicillium and Fusarium were the majority of the D soil,the endemic genera of H soil were Clonostachys and Purpureocillium,but Phoma and Leptosphaeria existed only in the D soil;（3） The Shannon-Wiener diversity index of the H soil was 2. 10,it was higher than that of the D soil（ 1. 98）,the evenness index of the H soil was 0. 91,and it was higher than that of the D soil（ 0. 79）. The biological characteristics of these cultivable fungi isolated from the wild fruit forest need to be further studied so as to be better applied in the soil pest control under the wild fruit forests.