Wang Jing-Qi, Wang Shu-Ping, Zhang Yuan, Lin Jia-Ning, Gao Xin, Zang Xiao-Miao, Zhao Qian
College of the Environment, Liaoning University, Shenyang 110036, China.
State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
Huan Jing Ke Xue. 2017 Apr 8;38(4):1403-1413. doi: 10.13227/j.hjkx.201609133.
Eukaryotic phytoplankton plays an important ecological function in river ecosystem. The 18S rRNA gene V4 variable region of the environmental samples in Liaohe river was sequenced by using 454 pyrosequencing technology. The reprehensive sequences of OTUs were annotated, and then the OTUs list was compared to the species list obtained by microscope observation. The phylogenetic tree was constructed based on the reprehensive sequences of OTUs and 18S rRNA genes of eukaryotic phytoplankton algae obtained from GenBank. The community structure characteristics of eukaryotic phytoplankton and its environmental impact indicators were further studied. In this study, we got 167901 high-quality sequences of 18S rRNA gene V4 region. These sequences were annotated to 424 OTUs, including 134 eukaryotic algae. The results of the high-throughput sequencing showed that bacillariophyta and chlorophyta were the dominant groups of the total phyla. The high-throughput sequencing also revealed the presence of Charophyta, Cryptophyta, Haptophyta and Chrysophyceae which were not observed by optical microscope. The phylogeny analysis clustered the Cryptophyta and Pyrroptata at phylum level. The different genera of Cryptophyta and part of families or genera of Pyrroptata were clustered and distinguished by phylogeny analysis. The results of RDA showed that NH-N, PO-P and NO were the most important environmental factors that affected the community structure. This study provided a new perspective to understand the diversity, community structure and influence factors of eukaryotic phytoplankton in Liaohe river. The study also indicated that high-throughput sequencing has great application potential in investigation of phytoplankton and the water environment quality assessment in Liaohe river.
真核浮游植物在河流生态系统中发挥着重要的生态功能。利用454焦磷酸测序技术对辽河环境样品的18S rRNA基因V4可变区进行测序。对OTUs的代表性序列进行注释，然后将OTUs列表与显微镜观察获得的物种列表进行比较。基于OTUs的代表性序列和从GenBank获得的真核浮游植物藻类的18S rRNA基因构建系统发育树。进一步研究了真核浮游植物的群落结构特征及其环境影响指标。在本研究中，我们获得了167901条18S rRNA基因V4区的高质量序列。这些序列被注释为424个OTUs，包括134种真核藻类。高通量测序结果表明，硅藻门和绿藻门是总门类中的优势类群。高通量测序还揭示了光学显微镜未观察到的轮藻门、隐藻门、定鞭藻门和金藻纲的存在。系统发育分析在门水平上对隐藻门和甲藻门进行了聚类。通过系统发育分析对隐藻门的不同属以及甲藻门的部分科或属进行了聚类和区分。冗余分析结果表明，NH-N、PO-P和NO是影响群落结构的最重要环境因素。本研究为了解辽河真核浮游植物的多样性、群落结构及影响因素提供了新的视角。该研究还表明，高通量测序在辽河浮游植物调查和水环境质量评估中具有巨大的应用潜力。
