岩性与植被类型对喀斯特土壤AM真菌群落的影响

Effects of Lithology and Vegetation Type on the Soil AM Fungi Community in Karst Region

运用巢式PCR和高通量测序技术,检测不同岩性和植被类型条件下喀斯特土壤丛枝菌根(arbuscular mycorrhizal,AM)真菌群落结构的变化,揭示不同岩性和植被类型条件下土壤中AM真菌群落结构的影响因子。高通量测序共获得185个操作分类单元(operational taxonomic unit,OTU),这些OTU可划分为7科9属,其中球囊霉属Glomus为研究区内的优势属。单因素方差和独立样本t检验分析表明,在不同岩性和植被类型条件下,土壤理化性质、AM真菌优势属均存在显著性差异。双因素方差分析结果表明,岩性和植被类型及两者的交互作用对AM真菌多样性及群落存在显著性影响。主坐标分析结果显示,在植被恢复阶段不同岩性条件下,AM真菌群落结构存在显著性差异。冗余分析表明,土壤的全磷、全钾、速效磷、砂粒含量、交换性镁离子影响AM真菌群落组成结构。综上可见,岩性和植被改变了土壤的全磷、全钾、速效磷、砂粒含量、交换性镁离子,并因此影响了土壤AM真菌的群落结构。

The changes of arbuscular mycorrhizal(AM)Fungi Community Structure in karst soil under different lithological and vegetation types were detected by nested PCR and high-throughput sequencing,and the influencing factors of AM Fungi Community Structure under different lithological and vegetation types were revealed.A total of 185 OTU(Operational Taxonomic Unit)were obtained from high-throughput sequencing.These OTU could be divided into 7 families and 9 genera,of which the Glomus was the dominant genus in the study area.The results of One-way ANOVA and independent sample t-test analysis showed that there were significant differences in soil physical and chemical properties and AM fungi dominant genus between sample plots under the different lithology and vegetation type conditions.The results of Two-way ANOVA showed that the lithology and vegetation type and the interaction between them had significant influence on the diversity and community of AM fungi.The results of PCoA showed that there were significant differences in the structure of AM fungi community under the different lithology and vegetation type conditions.The results of RDA showed that soil total phosphorus,total potassium,available phosphorus,sand content and exchangeable magnesium ions affected the structure of AM fungal community.In summary,the research results showed that the lithology and vegetation type changed soil total phosphorus,total potassium,available phosphorus,sand content,exchangeable magnesium ions in soil,and thus affected the structure of AM fungi community in soil.