Abstract: In order to explore the structure and driving factors of soil fungal community in different grasslands types in Inner Mongolia,we studied the desert-typical-meadow steppes in Inner Mongolia,which were distributed continuously from west to east. High-throughput sequencing was used to analyze the characteristics of soil fungal community and reveal the driving factors of fungal community in combination with soil physical and chemical properties. The results showed that the soil was alkaline and mainly sandy texture in the three types of grasslands,and the soil moisture content was significantly different (P＜0.05). The soil nutrient content (soil organic matter,total nitrogen,and total phosphorus) was the lowest in desert steppe. The Shannon index,Chao 1 index,and Pielou evenness index of soil fungal communities in desert steppe were the highest. There were significant differences in soil fungal community structure of different types of grasslands (P＜0.05). Ascomycota,Basidiomycota,Mortierellomycota,and Chytridiomycota were the dominant fungal phyla. Mortierella and Fusarium were the common dominant genera. The Saprotroph fungi were dominant in grassland soil,and there was no significant difference in the abundance of major functional groups. Redundancy analysis suggested that soil moisture content was the main driving factor of soil fungal communities in different types of grasslands in Inner Mongolia.

Key words: Grassland types, Soil fungi, Community structure, Function prediction, Environmental factors

摘要： 为探究内蒙古不同类型草原土壤真菌群落结构及其影响因子，以内蒙古中东部自西向东连续分布的荒漠-典型-草甸草原为研究对象，采用高通量测序的方法分析土壤真菌群落特征，结合土壤理化性质揭示真菌群落的驱动因子。结果表明：三种草原的土壤均呈碱性且以沙粒为主，土壤含水率差异显著(P＜0.05)；荒漠草原土壤养分含量(土壤有机质、总氮和总磷)最低，草甸草原土壤养分含量最高；荒漠草原土壤真菌的Shannon指数、Chao 1指数和Pielou均匀度指数最高；不同类型草原土壤真菌群落结构具有显著差异(P＜0.05)；子囊菌门(Ascomycota)、担子菌门(Basidiomycota)、被孢霉门(Mortierellomycota)和壶菌门(Chytridiomycota)是优势真菌门；被孢霉属(Mortierella)和镰刀菌属(Fusarium)是共有优势属；草原土壤真菌以腐生营养型为主，主要功能群丰度无明显差异；冗余分析表明土壤含水率是不同类型草原土壤真菌群落的主要驱动因子。

关键词: 草原类型, 土壤真菌, 群落结构, 功能预测, 环境因子