洞庭湖和鄱阳湖水体细菌空间分布特征及驱动机制

为了探讨洞庭湖和鄱阳湖水体细菌的群落组成、空间分布特征及其驱动机制，于2017年9月，采用高通量测序技术、基于16S rRNA分子标记进行单分子测序，分别对两湖共57个位点的水体细菌群落组成进行了研究，同步监测了水体的理化指标。结果表明：洞庭湖和鄱阳湖共发现水体细菌20门42纲93目191科533属，在门水平上，洞庭湖和鄱阳湖的水体细菌组成均以放线菌门、蓝细菌门和变形菌门为主；主成分分析结果表明，两湖水环境条件有显著性差异，鄱阳湖的空间差异性大于洞庭湖；Mantel分析表明显著影响蓝细菌类群和其他类群组成的因素较为一致，在洞庭湖以物理环境因子和营养盐因子为主，而鄱阳湖以物理环境因子为主；零模型分析结果显示随机性过程为两湖水体细菌的群落构建机制的主要成分，占比分别为58.8%和79.7%。总体来说，鄱阳湖水环境空间异质性更高，水体细菌受到一些水文水动力学因子介导的物理环境因子影响，且其群落构建机制由随机性过程主导；洞庭湖水环境空间异质性较低，水体细菌受到物理环境因子和营养盐因子的共同影响，其群落构建机制由随机性过程和确定性过程共同决定。认识两湖水体细菌在空间上的分布及影响因素差异，对两湖...

Spatial distribution pattern and effecting factors of aquatic bacteria in Lake Dongting and Lake Poyang

In order to investigate the community compositions and distribution patterns of bacterioplankton in Lake Dongting and Lake Poyang, and identify their affecting factors, we studied the compositions of aquatic bacteria community of Lake Dongting and Lake Poyang in 57 sampling sites through high-throughput sequencing technology in September 2017. The physical and chemical parameters of these samples were detected. The results showed a total of 20 phyla, 42 classes, 93 orders, 191 families, and 533 genera. At the phylum level, Actinobacteria, Cyanobacteria and Proteobacteria were the main bacteria in Lake Dongting and Lake Poyang. The results of principal component analysis showed that environmental heterogeneity in Lake Poyang was higher than that in Lake Dongting. Mental tests showed that the main factors affecting the compositions of cyanobacteria and other groups were ammonia-nitrogen, nitrate nitrogen, total nitrogen (TN), phosphate phosphorus (PO^3-₄-P), total phosphorus (TP), water temperature (WT), electric conductivity (EC) and salinity (Sal) in Lake Dongting and PO^3-₄-P, WT, EC and Sal in Lake Poyang. The results of the null model showed that the stochastic process was the main driver of aquatic bacteria community assembly. Overall, Lake Poyang was more affected by stochastic process and less deterministic process under higher environmental heterogeneity, whereas Lake Dongting was affected by both stochastic process and deterministic process. Known the spatial distributions and community assembly mechanisms of aquatic bacteria are of great guiding value to the monitoring and evaluation of Lake Dongting and Lake Poyang.