不同坡位处沙柳沙障真菌群落组成及其影响因素

Fungal community composition of Salix psammophila sand barriers at different slope positions and its influencing factors

为探究不同坡位对沙柳Salix psammophila沙障沙埋部真菌群落组成及多样性的影响,以刚铺设于平缓沙丘的沙障作为对照(CK),采用野外原位取样与室内指标测定的方法,结合Illumina MiSeq测序技术,揭示影响真菌群落组成及多样性的主要因子。结果表明:(1)不同坡位处真菌优势菌为粪壳菌纲Sordariomycetes和蘑菇纲Agaricomycetes,相对丰度分别为69.10%和13.78%,随坡位的下降,散囊菌纲Eurotiomycetes呈增加趋势,而座囊菌纲Dothideomycetes、锤舌菌纲Leotiomycetes和盘菌纲Pezizomycetes呈先增大后减少的趋势;(2)坡下铺设的沙柳沙障腐烂程度较坡中与坡上更大,真菌群落多样性与丰富度均为:坡下>坡中>坡上;(3)LEfSe多级物种差异分析表明,田头菇属Agrocybe、粘鞭霉属Gliomastix和木霉属Trichoderma为各组中具有显著性差异的物种(P<0.05);(4)冗余分析(redundancyanalysis,RDA)结果表明,优势真菌和群落多样性均受到多种环境因子的综合影响,土壤含水率和沙障木质素含量是显著影响菌群丰度和群落多样性的主要环境因子(P<0.05)。本研究结果为进一步探究沙柳沙障腐烂过程中真菌的生态功能提供理论基础。

To investigate the effect of slope position on the composition and diversity of fungal communities in the sand-buried parts of Salix psammophila sand barriers,sand barriers just laid on gentle dunes were set up as a control(CK),and in situ sampling in the field and indoor index determination combined with Illumina MiSeq sequencing technology were carried out.The results showed that the dominant fungi at different slopes were Sordariomycetes and Agaricomycetes,with a relative abundance of 69.10%and 13.78%,respectively.With the going down of slope position,Eurotiomycetes appeared increasingly,while the species of Dothideomycetes,Leotiomycetes and Pezizomycetes increased first and then decreased.The decay degree of the sand barrier set at the bottom of the slope was greater than that at the middle and top of the slope.Accompanied by the different decay degrees of the sand barrier,the diversity and richness of the fungal community at different slope positions showed a variation of bottom>middle>top.LEfSe multilevel species difference analysis indicated that the species of Agrocybe,Gliomastix,and Trichoderma were significantly different among the experimental groups(P<0.05).The results of redundancy analysis(RDA)showed that the dominance and community diversity of fungi were affected by a variety of environmental factors.Soil moisture content and sand barrier lignin content were the main environmental factors that significantly affected the abundance and community diversity of fungi(P<0.05).Further investigation of the ecological functions of fungi during the decay process of S.psammophila sand barriers is needed.