大冶湖和朱婆湖中微型和超微型真核浮游生物多样性研究

Eukaryotic Nanoplankton and Picoplankton Diversity in Daye Lake and Zhupo Lake

应用常规浮游生物调查策略以及18S rRNA的V4可变区进行高通量测序,并结合实时荧光定量PCR技术以及相关统计学分析方法,在大冶湖和朱婆湖分别选取6个和3个采样站位,于2017年春季(4月)对两个湖泊中粒级5~20μm的部分微型(Nano粒级,2~20μm)和超微型(Pico粒级,≤5μm)真核浮游生物的多样性进行初步探究。结果表明,大冶湖超微型真核浮游生物物种相对丰度最高的是隐藻门种类(约占OTU总数的28%),5~20μm的部分微型真核浮游生物物种相对丰度最高的分别是纤毛虫(约19%)和绿藻门种类(约18%);朱婆湖超微型真核浮游生物物种相对丰度最高的分别是纤毛虫(约23%)和顶复门种类(约23%),5~20μm的部分微型真核浮游生物物种相对丰度最高的是硅藻门种类(约33%)。大冶湖和朱婆湖中,两种粒级真核浮游生物的多样性之间均存在显著性差异,且大冶湖的真核浮游生物多样性高于朱婆湖。大冶湖超微型真核浮游生物多样性高于5~20μm的部分微型真核浮游生物,朱婆湖两粒级真核浮游生物多样性无显著性差异。大冶湖中的超微型真核浮游生物种类最为繁多,生物多样性最高。与真核浮游生物自身粒级大小的影响相比,水环境差异可能是影响真核浮游生物多样性更为重要的因素。

In this study, we explored the diversity of eukaryotic nanoplankton(5-20μm) and eukaryotic picoplankton(≤5μm) in Daye Lake and Zhupo Lake, aiming to explore the effect of eukaryotic plankton on eutrophication and provide guidance for evaluating the two lakes. In April 2017, water samples were collected at 6 sampling sites on Daye Lake and 3 sampling sites on Zhupo Lake. Conventional survey methods for plankton, along with high-throughput sequencing technology, real-time fluorescence quantitative PCR and statistical methods were used to analyze the samples. The relative abundance of eukaryotic picoplankton in Daye Lake was highest for Cryptophyta, accounting for 28% of the total Operational Taxonomic Unit(OTU), and the relative abundance of eukaryotic nanoplankton was highest in Ciliophora(19% of total OTU) and Chlorophyta(18%). In Zhupo Lake, the relative abundance of eukaryotic picoplankton was highest in Ciliophora(23%) and Apicomplexa(23%), and the relative abundance of some eukaryotic nanoplankton was highest in Bacillariophyta(33%). There was a significant difference in the diversity of eukaryotic plankton of both cell sizes between Daye Lake and Zhupo Lake, and the diversity of eukaryotic plankton in Daye Lake was higher than in Zhupo Lake. In Daye Lake, the diversity of eukaryotic picoplankton was higher than that of the eukaryotic nanoplankton, and no significant difference was detected in the diversity of the two types of eukaryotic plankton in Zhupo Lake. The eukaryotic picoplankton species in Daye Lake were most abundant and the biodiversity was also higher. Compared with the cell size of eukaryotic plankton, differences in the water environment appear to be more important for eukaryotic plankton biodiversity.