退化高寒草地土壤真菌群落与土壤环境因子间相互关系

Relationship between soil fungal community and soil environmental factors in degraded alpine grassland

摘要:

[目的]为探究祁连山高寒草地退化过程中土壤真菌群落分布特征与土壤环境因子间的相互关系。[方法]利用Illumina Miseq PE250高通量测序技术对轻度、中度和重度退化草地土壤真菌群落结构变化及其多样性进行分析，并对土壤真菌群落与土壤环境因子的相互关系进行冗余分析（RDA）。[结果]随着退化程度加剧，土壤pH呈现出升高趋势，电导率呈现出先升高后降低趋势，土壤含水量、有机碳、全氮、全磷和全钾含量均逐渐降低。高通量测序共得到750575条有效序列和5788个OTUs；各试验点样地中真菌群落Chao1指数和Shannon-Wiener指数变化各异。在门分类水平上，子囊菌门（Ascomycota）、担子菌门（Basidiomycota）、接合菌门（Zygomycota）、球囊菌门（Glomeromycota）和壶菌门（Chytridiomycota）是各草地土壤的优势类群。RDA分析表明，土壤速效钾、全氮、速效氮和有机碳是祁连山不同退化高寒草地土壤真菌群落分布的主要驱动因子。[结论]祁连山不同退化高寒草地土壤真菌群落间差异明显，土壤环境因子是影响土壤真菌群落分布的重要因素。

Abstract:

[Objective] To explore the relationship between soil fungal community structure and soil environmental factors of the degradation process of alpine grassland in Qilian Mountains.[Methods] We analysed the changes and diversity of fungal community structure in lightly, moderately and severely degraded grassland by Illumina Miseq PE250 high throughput sequencing technology, and redundancy analysis (RDA) of the relationship between soil fungal community structure and soil environmental factors was analysed.[Results] With the aggravated degree of deterioration, soil pH was increased, electrical conductivity was increased first and then decreased, soil water content, organic carbon, total nitrogen, total phosphorus and total potassium were gradually decreased. We obtained a total of 750575 effective sequences and 5788 OTUs by high throughput sequencing, the Chao1 and Shannon-Wiener index of fungal communities varied in different samples. The fungal communities' dominant phyla of all soil samples were Ascomycota, Basidiomycota, Zygomycota, Glomeromycota and Chytridiomycota. RDA analysis showed that soil available potassium, total nitrogen, available nitrogen and organic carbon were the important driving factors for the distribution of soil fungal community structure in different degraded alpine grassland of Qilian Mountains.[Conclusion] The soil fungal community structure was significantly different in different degraded alpine grassland, and soil environmental factors was a important factor influenced the distribution of soil fungal community structure in Qilian Mountains.