东祁连山高寒草地土壤可培养真菌多样性分析

为了解东祁连山高寒草地土壤可培养真菌的多样性,选择有代表性的4类草地类型(珠芽蓼草地、禾草草地、沼泽草地、嵩草草地),运用稀释平板法和基于ITS rDNA基因序列的系统发育分析对其土壤中可培养真菌多样性进行研究,同时应用生态学评价方法进行分析。用PDA培养基、PSA培养基、玉米粉琼脂培养基和马丁氏-孟加拉红培养基从土壤样品中分离得到76株真菌,通过形态观察选取30株有代表性的菌株进行基于ITS rRNA基因序列的系统发育多样性分析。结果表明,鉴定所得菌株可分为22个属的26个种,绝大多数属于半知菌亚门和接合菌亚门真菌;物种的丰富度(S)、Shannon-Wiener多样性指数(H)、Simpson优势度(D)和Pielou均匀度指数(J)变化范围分别为15~18,2.47~2.81,0.89~0.93,0.91~0.97;青霉属(Penicillium)真菌为珠芽蓼草地、沼泽草地和嵩草草地的优势菌,镰孢菌属(Fusarium)真菌为禾草草地的优势菌,柔菌属真菌(Doratomyces)为沼泽草地的优势菌,被孢霉属(Mortierella)、柔菌属、小球腔菌属(Leptosphaeria)、毛霉属(Mucor)、木霉属(Trichoderma)、地丝菌属(Geomyces)和镰孢属为4类草地的常见属。另外,4类草地都有大于10%的分离菌种暂时无法确定其分类地位,极可能是新种;东祁连山高寒草地土壤真菌多样性丰富,其多样性和草地类型的特异性有着密切的关系,东祁连山高寒草地有着丰富的土壤真菌资源,存在潜在的开发价值。

A study on the diversity of soil cultured fungi in the alpine grassland of Eastern Qilian Mountains

In order to assess the diversity of soil cultured fungi in alpine grassland of Estern Qilian Mountains, 4 types alpine grasslands (Polygonum grassland, grass grassland, swamp grassland, Kobresia grassland) were selected to investigate their soil cultured fungi to understand their diversity by dilution plate technique and ITS rDNA sequence analysis, the soil cultured fungi were evaluted by economic efficiency analysis methods. 76 strains fungi were isolated by PDA, PSA, Maize Powder Media and Rose Bengal Medium. 30 typical strains were analyzed by ITS rDNA sequence analysis.The resulted showed, 30 strains belong to 22 genera, 26 species, most of them belong to imperfect fungi and zygomycetes. Species abundance (S), Shannon-Wiener index (H), Simpson dominance index (D) and Pielou evenness index (J) range were 15-18, 2.47-2.81, 0.89-0.93, 0.91-0.97, respectively. Penicillium spp. were dominant fungi in Polygonum grassland, swamp grassland and Kobresia grassland, Fusarium spp. were dominant fungi in grass grassland, Doratomyces spp. were dominant fungi in swamp grassland, Mortierella, Doratomyces, Leptosphaeria, Mucor, Trichoderma, Geomyces and Fusarium were common genera in four types grassland. In addition, more than 10% fungi strains could not clarify the taxonomic status temporarily, which might be new species; The results indicate that the diversity of soil fungi were very abundant in the alpine grassland of Eastern Qilian Mountains, and there exist close corelation between fungal diversity and grassland types, finally, it is concluded that there have abundance soil fungi in the alpine grassland of Eastern Qilian Mountains, which were deserved for further study and having huge exploitation value.