基于高通量测序探讨大宁河不同水华期真核浮游生物群落组成

Community Structure Characteristics of Eukaryotic Plankton During the Cyanobacterial Blooms Using High-Throughput Sequencing

为探究不同水华时期对真核浮游生物群落组成的影响,对三峡库区大宁河支流水华中、后期进行采样,通过镜检法对浮游植物进行定性和定量分析,并利用Illumina MiSeq测序平台对真核浮游生物18S rRNA基因的V4可变区进行测序,结果表明:大宁河采样点水华中期(DNH1)优势蓝藻主要为铜绿微囊藻(Microcystis aeruginosa)和水华鱼腥藻(Anabaena flos-aquae),而水华末期(DNH2)以隶属硅藻门的直链藻属(Melosira)占优势.水华中期和末期真核浮游生物分别涵盖了9纲989种和9纲922种.水华中期绿藻纲所占比例最大,为34.88%,水华末期羽改硅藻纲所占比例最大,为31.42%.此外,与中期相比,水华末期硅藻纲和前口纲的丰度比水华中期高,但双壳纲和颚足纲的丰度明显降低,表明不同水华时期,真核浮游生物群落结构变化显著,同时,真核浮游生物群落变化可能影响蓝藻水华的生消过程.

To explore the effect of cyanbacterial bloom on the composition of eukaryotic plankton community,a survey was conducted in the Daning river,a tributary of the Three Gorges Reservoir,during the middle and last stages of the bloom.Qualitative and quantitative analyses of phytoplankton were carried out with microscopic examination,and the 18S rRNA gene V4 variable region was sequenced using the 454-pyrosequencing technology.The results indicated that Microcystis aeruginosa and Anabaena flos-aquae were the most dominant species in the middle stage of the bloom,but Melosira belonging to Bacillariophyta was dominant in the last stage.Eukaryotic planktons in the bloom involved 9 classes(989 species)and 9 classes(922 species)at the middle and the last stage,respectively.In the middle stage,Chlorophyceae was the dominant group,accounting for about 34.88%of the total biomass,while Pennatae was the dominant group,accounting for 31.42%of the total,in the last stage.Moreover,compared with that in the middle stage,the abundance of Diatomacae and Prostomatea increased and the abundance of Bivalvia and Maxillopoda dropped significantly in the last stage,suggesting that a significant change existed in the community of eukaryotic micro-plankton in different stages of the bloom,and the change of the eukaryotic micro-plankton community might have an effect on the fluctuation of cyanobacterial bloom.