拉萨河下游城区段水域细菌多样性变化特征  

Characteristics of bacterial diversity changes in the watershed of the lower Lhasa River

作　　者：汪昱言 刘怡萱 李星冉 董石 张继峰 拉琼[1,2,3] 曹鹏熙 WANG Yuyan;LIU Yixuan;LI Xingran;DONG Shi;ZHANG Jifeng;LA Qiong;CAO Pengxi(Key Laboratory of Biodiversity and Environment on the Qinghai-Tibetan Plateau,Ministry of Education,School of Ecology and Environment,Xizang University,Lhasa 850000,China;Nagqu Mitika,Alpine Wetland Ecosystem,Observation and Research Station of Tibet Autonomous Region,Xizang University,Lhasa 850000,China;Collaborative Innovation Center for Ecological Civilization of the Qinghai-Tibetan Plateau,Xizang University,Lhasa 850000,China)

机构地区：[1]西藏大学生态环境学院青藏高原生物多样性与生态环境保护教育部重点实验室,西藏拉萨850000 [2]西藏大学那曲麦地卡高寒湿地生态系统西藏自治区野外科学观测研究站,西藏拉萨852000 [3]西藏大学青藏高原生态文明协同创新中心,西藏拉萨850000

出　　处：《冰川冻土》2025年第2期537-548,共12页Journal of Glaciology and Geocryology

基　　金：西藏自治区科技计划重点研发项目(XZ202301ZY0006G;XZ202501JD0016);那曲市科技计划重点研发项目(NQKJ-2023-15);西藏自治区自然科学基金重点项目(XZ202301ZR0014G);中央财政支持地方高校建西藏麦地卡湿地站建设项目(藏财科教指[2023]1号,[2024]1号)资助。

摘　　要：拉萨河是雅鲁藏布江五大支流之一,维护拉萨河流生态系统健康发展对拉萨市生态安全屏障建设、生态文明高地建设及可持续发展具有重要意义。本研究在拉萨河下游城区段进行水体微生物样品采集及环境因子测定,通过高通量测序技术对拉萨河下游城区段水体细菌群落多样性、结构特征及群落组装过程进行分析,结合水体理化性质探究环境因子对拉萨河水体微生物多样性的影响。对拉萨河下游120 km水域的12个样点水体进行细菌扩增子测序,结果统计得到39个门,101个纲,289个目,493个科,1004个属和1954个种的细菌,表明拉萨河下游水域细菌多样性较丰富;水体上段和下段的细菌群落组成具有较高的相似性,优势菌门为变形菌门(Proteobacteria)、厚壁菌门(Firmicutes)、放线菌门(Actinobacteria)、浮霉菌门(Planctomycetes)和拟杆菌门(Bacteroidetes)等;优势菌属为Limnohabitans、Exiguobacterium等;对拉萨河下游城区段水体细菌门和属水平的进行对比分析可得,属水平上的细菌群落组成相似度更低。通过中性模型分析可得,拉萨河下游城区段水体细菌群落受到随机性过程和确定性过程的共同影响,但以随机性过程为主导。通过共现性网络分析可得,水体细菌群落的连接主要以正相关边为主,下段水体表现出更强的网络复杂性和联通性,在上段和下段水体细菌共现性网络中变形菌门(Proteobacteria)、放线菌门(Actinobacteria)、拟杆菌门(Bacteroidetes)的占比最高。通过Mantel分析可得,水体CO_(2)浓度对上段水体细菌群落具有显著的正相关影响,其余环境因子对其影响不显著;pH、水体温度、盐度、光照强度、水体溶解氧对下段水体细菌群落具有显著的正相关影响。通过研究拉萨河下游城区段水体细菌群落结构、多样性变化及群落组装机制,有助于深入了解高原河流特有的微生物群落结构和功能,评估全球变Lhasa River is one of the five major tributaries of the Yarlung Tsangpo River.Maintaining the healthy development of the Lhasa River ecosystem is of great significance to the construction of the ecological se⁃curity barrier,ecological civilization highland,and sustainable development in Lhasa.In this study,we collect⁃ed microbial samples from the lower Lhasa River.We determined the environmental factors,analyzed the diver⁃sity of bacterial communities,structural characteristics,and community assembly process in the lower Lhasa River by high-throughput sequencing,and explored the influence of environmental factors on the microbial diver⁃sity of the Lhasa River by combining with the physical and chemical properties of the water body.The results of bacterial amplicon sequencing at 12 sample sites within 120 km of the lower Lhasa River revealed 39 phyla,101 orders,289 orders,493 families,1004 genera,and 1954 species of bacteria,indicating that the bacterial com⁃munities in the lower Lhasa River had a rich bacterial diversity and that the composition of the bacterial commu⁃nities in the upstream and downstream sections of the water body is highly similar,with the dominant phyla be⁃ing Proteobacteria,Firmicutes,Actinobacteria,Planctomycete and Bacteroidetes ect.;the dominant genera were Limnohabitans,Exiguobacterium,etc.;Comparative analyses of the bacterial phylum and genus levels in the water body of the downstream of the Lhasa River showed that the similarity of the bacterial community com⁃positions at the genus level was even lower.The neutral model analysis shows that the bacterial community in the water body of the downstream of the Lhasa River is affected by both stochastic and deterministic processes,but the stochastic process is dominant.Co-occurrence network analysis showed that the connectivity of bacterial communities in water bodies was mainly dominated by positive correlation edges,with the lower section of wa⁃ter bodies showing stronger network complexity and connectivity.Proteobacteria

关 键 词：拉萨河 水体细菌 多样性 群落组装 河流生态系统 

分 类 号：Q938[生物学—微生物学]