白洋淀超微真核藻的空间分布特征及关键影响因子  

Spatial distribution characteristics of photosynthetic picoeukaryotes community structure and its impacting factors in Lake Baiyangdian

作　　者：雷瑾 史小丽[2] 张民[2] 李胜男 陈开宁[2] 杨州[1] LEI Jin;SHI Xiaoli;ZHANG Min;LI Shengnan;CHEN Kaining;YANG Zhou(Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, Nanjing 210023, P. R. China;State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, P. R. China;Hunan Academy of Agricultural Sciences, Changsha 410125, P. R. China)

机构地区：[1]南京师范大学生命科学学院,江苏省生物多样性与生物技术重点实验室,南京210023 [2]中国科学院南京地理与湖泊研究所湖泊与环境国家重点实验室,南京210008 [3]湖南省农业科学院,长沙410125

出　　处：《湖泊科学》2019年第6期1559-1569,共11页Journal of Lake Sciences

基　　金：国家自然科学基金项目(31670462,41877544)资助

摘　　要：超微真核藻个体微小、比表面积大,具有高效的碳吸收速率,对水体初级生产力具有重要的贡献.目前对淡水超微真核藻的认知还非常有限.于2017年5月对白洋淀进行采样调查,结合流式细胞术和高通量测序技术探究了白洋淀超微真核藻群落结构的空间分布特征及关键环境影响因子.结果表明,白洋淀超微真核藻的平均丰度为7.59×10^4 cells/ml,且随着营养水平的升高呈现先增加后降低的变化趋势.回归分析表明,超微真核藻丰度在中营养水平水域主要受溶解性总磷和TN/TP影响,在富营养水域主要与盐度有关.测序比对结果表明在纲水平上白洋淀超微真核藻主要以绿藻纲Chlorophyceae、硅藻纲Bacillariophyceae、中心硅藻纲Coscinodiscophyceae、金藻纲Chrysophyceae为主,不同区域差异不大.但在操作分类单元(Operation Taxonomy Units,OTU)水平上,超微真核藻群落结构在白洋淀不同营养状态湖区存在显著差异,中营养水域主要类群为栅列藻科Scenedesmaceae,近囊胞藻属Paraphysomona sp.,定鞭藻纲Haptophyceae和甲藻纲Dinophyceae为主,而富营养水域主要类群为红球藻科Haematococcaceae,金藻纲的Chromulinale sp.和Chrysophycea sp..Bioenv分析表明,对超微真核藻群落组成影响最大的环境因子是溶解性总氮、溶解性总磷、TN/TP、硝态氮、溶解氧.本研究表明超微真核藻的群落结构存在较明显的环境异质性,对白洋淀水体富营养化状态有很好的指示.Photosynthetic picoeukaryotes(PPEs) are major primary producers in lakes, due to their small size, high surface-to-volume ratio and high carbon-specific rate of carbon uptake. However, their diversity is poorly understood in freshwater ecosystems. PPEs community structure of Lake Baiyangdian was investigated in the May 2017, to explore their spatial distribution features and their relationship with environmental factors. The results based on flow cytometric analysis showed that the average abundances of PPEs were 7.59×10^4 cells/ml, and showed a peak at a certain nutrient level. Regression analysis showed that the abundance of PPEs was affected by total dissoloved phosphorus(TDP) and TN/TP in the lake regions with mesotrophic states, but was related to salinity in the lake regions with eutrophic states. The sequencing results indicated that PPEs were mainly dominated by Chlorophyceae, Bacillariophyceae, Coscinodiscophyceae and Chrysophyceae. At finer level, PPEs community structure was different in the lake regions with two trophic states. Scenedesmaceae, Paraphysomona sp., Haptophyceae and Dinophyceae were prevalent in mesotrophic lake regions, whereas, Haematococcaceae, Chrysophycea sp. and Chromulinale sp. were dominant in eutrophic lake regions. Bioenv analysis results revealed that PPEs community structure was mainly related to those environmental factors, including total dissoloved nitrogen, TDP, TN/TP, nitrate nitrogen and dissoloved oxygen. PPEs structure seemed to be a good ecological indicator for the trophic states of lakes.

关 键 词：白洋淀 超微真核藻 群落结构 环境因子 流式细胞仪 

分 类 号：X524[环境科学与工程—环境工程]