网箱养殖对刘家峡水库浮游细菌群落组成及影响因素分析

Effect of cage culture on community structure and influencing factors of bacterioplankton in Liujiaxia Reservoir

为了评价网箱养殖对刘家峡水库浮游细菌群落结构和多样性的影响,于2016年10月份对刘家峡水库6个生态位点进行水样采集,采用高通量测序技术分析了浮游细菌群落特征。结果表明,刘家峡水库浮游细菌主要由变形菌门、放线菌门、蓝藻门、拟杆菌门等11个门,ACK-M1-norank、聚球藻属、鞘氨醇单胞菌属、红球菌属、β变形菌属和Pelagibacteraceae-uncultured等73个属组成,浮游细菌丰度和多样性指数由水库上游至下游依次降低,网箱养殖活动使附近水体的理化性质发生变化,并导致浮游细菌多样性降低。聚球藻属、黄杆菌属、放线菌属、Limnohabitans属和不动杆菌属的种类相对丰度受网箱养殖活动影响敏感。冗余分析表明NO-3-N、TP和TN是影响刘家峡水库浮游细菌群落结构的主要水环境因子,共同解释了55.11%的群落变异。

Liujiaxia Reservoir is the main source of water for the surrounding urban and the important breeding base for cold water fish.Six surface water samples were collected and analyzed by using high-throughput sequencing technologies in October 2016 to evaluate the effect of cage culture on community structure and diversity of bacterioplankton.Meanwhile,five essential environmental factors were investigated from Liujiaxia reservoir at the same time.The results showed that the bacterioplankton of Liujiaxia reservoir was divided into 11 major phylogenetic groups,including Proteobacteria,Actinobacteria,Cyanobacteria and Bacteroidetes,etc.At the genus level,the mainly phylogenetic groups distributed in 73 different genus,which included ACK-M1-norank,Synechococcus Sphingomonas,Rhodococcus,Limnohabitans,Pelagibacteraceae-uncultured,etc.The diversity index and abundance of the bacterioplankton decreased systematically from upstream to downstream.The physicochemical property of nearby water changed a lot caused by cage culture activities,and this led to the decrease of bacterioplankton diversity.The relative abundance of Synechococcus,Flavobacterium,Actinobacteria,Limnohabitans and Acinetobacter were sensitive to cage culture.The physical and chemical properties of the water in cage culture were changed,and lead to lower the diversity of bacterioplankton,The results of redundancy analysis for the relationship between the 73 genus of the bacterial and 5 essential environmental factors showed that NO-3-N、TP and TN were the main environmental factors affecting the distribution characteristics of the bacterioplankton community,and 55.11%of the phytoplankton community differences were thought to be related to changes in water environment.Above the results could beprovide a foundation for investigating the relationship between healthy culture of cage and bacterioplankton in Liujiaxia Reservoir.