局域尺度麦田土壤微生物群落构建过程及其驱动因素

Soil Microbial Community Construction Processes and Its Driving Factors in Wheat Field at Local-scale

为探究局域尺度麦田土壤微生物群落构建过程,本研究采集河南省济源市小麦种植户麦田土壤,应用高通量测序技术,研究局域尺度下麦田土壤细菌群落结构、群落构建过程及其影响因素。结果表明:①土壤细菌群落中优势菌门是酸杆菌门(Acidobacteria)和变形菌门(Proteobacteria)。通过曼特尔检验以及冗余分析发现有机质和全氮对细菌群落结构影响显著(P<0.05)。②细菌分子生态网络中不同细菌类群之间以合作关系为主,关键物种来自拟杆菌门(Bacteroidetes)、酸杆菌门和变形菌门。③细菌群落在系统发育上聚类,有机质和有效磷对细菌群落系统发育影响显著(P<0.05)。④确定性过程和随机性过程在细菌群落构建中的贡献率分别为74.59%和25.41%。⑤曼特尔检验发现最近物种指数(βNTI)值与有机质、全氮、全磷含量变化呈显著正相关(P<0.05)。有机质、全氮、全磷含量差异的增大导致细菌群落从同质性选择以及均质扩散向异质性选择过程的转变。综上所述,本研究发现确定性过程在局域尺度麦田土壤细菌群落构建中占主导地位,土壤有机质、全氮、全磷是影响细菌群落构建的关键环境因素。有机质和全氮还对细菌群落结构有显著影响。本研究有利于对局域尺度下麦田生态系统土壤微生物多样性形成机制的认识。

In order to explore soil microbial community construction processes in wheat field at local-scale,soil samples were collected from wheat fields in Jiyuan City,Henan Province,and high-throughput sequencing technology was used to study soil bacterial community structure,community construction process and its influencing factors.The results showed that:1)The dominant phyla were Acidobacteria and Proteobacteria in soil bacterial community.Mantel test and redundancy analysis found that organic matter and total nitrogen had significant effects on bacterial community structure(P<0.05).2)The different bacterial groups in the bacterial molecular ecological network were dominated by cooperative relationship.The key species were from Bacteroidetes,Acidobacteria and Proteobacteria.3)Bacterial communities were clustered phylogenetically,and organic matter and available phosphorus had significant effects on bacterial community phylogeny(P<0.05).4)The contribution rates of deterministic process and stochastic process in bacterial community construction were 74.59%and 25.41%,respectively.5)Mantel test found that theβNTI value was significantly positively correlated with the changes of organic matter,total nitrogen and total phosphorus contents(P<0.05).The increases in the differences of organic matter,total nitrogen and total phosphorus contents led to the transformation of bacterial communities from homogeneous selection and homogeneous diffusion to heterogeneous selection.Conclusively,this study found that deterministic processes dominated the construction of soil bacterial communities in local-scale wheat fields,and organic matter,total nitrogen and total phosphorus were the key environmental factors affecting bacterial community construction.Organic matter and total nitrogen also had significant effects on bacterial community structure.This study contributes to the understanding of the formation mechanism of soil microbial diversity in wheat field ecosystems at the local scale.