磷化工区农田土壤中丰富和稀有细菌群落构建过程及功能差异

Assembly Process and Functional Differentiation Between Abundant and Rare Bacterial Community in Farmland Soil near Phosphorus Chemical Industrial Area

摘要:

运用高通量测序技术，研究了磷化工区盛行风向下方不同距离农田表层土壤中细菌丰富和稀有亚群的群落结构、构建过程和功能差异。结果表明：放线菌门(Actinobacteria)、变形菌门(Proteobacteria)和绿弯菌门(Chloroflexi)是研究区表层土壤细菌丰富和稀有亚群中的优势菌门。靠近化工区的高镉含量土样中(D1)两种细菌亚群的多样性低于其他距离较远的低镉含量样品，且亚群群落组成不同，但功能组成无明显差异。相关分析表明，土壤pH和镉含量是影响两种细菌亚群的主要因素，其中前者更为关键。稀有细菌亚群的群落和功能多样性均高于丰富细菌亚群。中性模型分析表明，丰富细菌亚群和稀有细菌亚群的群落构建过程分别由随机性和确定性过程主导。

Abstract:

This study used high-throughput sequencing technology to analyze the community structures, assembly processes, and functional differences of abundant and rare bacterial sub-communities in the farmland topsoils with different distances below the prevailing wind direction of a phosphorus chemical industrial area. The results showed that Actinobacteria, Proteobacteria and Chloroflexi were the dominant bacterial phyla in both sub-communities. The diversities of two sub-communities in soil sample close to industrial area with high Cd content were lower than those in the other distant soils with low Cd contents. Significant differences in community compositions were observed between these two soil types, while their functional compositions were similar. Correlation analysis showed that soil pH and Cd were the main factors affecting the two bacterial sub-communities, with the former being more critical. Rare bacteria maintained higher community and functional diversity compared to abundant bacteria. Neutral modeling analyses indicated that community assembly processes of abundant and rare bacterial sub-communities were represented by stochastic and deterministic processes, respectively.