洛阳江流域真核浮游生物多样性研究

The Diversity of Eukaryotic Plankton in Luoyang River

以18S rRNA基因为分子标记,应用高通量测序和水质监测技术对洛阳江流域后坂水库(HB)、惠女水库(HN)、福滨街桥(FB)、前后埭交界处(QHD)、杏宅水闸(XZ)和洛阳桥(LY)共6个代表性断面水体的真核浮游生物多样性及其与环境因子相关性进行了分析.结果表明:HB和HN水质状况较好,其水质指标类别均为Ⅱ级以上;XZ和LY水质相对较差,除个别水质指标为Ⅱ级以上,其他指标均为Ⅲ级以下;不同断面水体真核浮游生物结构组成不同,HN物种丰富度较高,物种分布较为均匀,LY物种丰富度和均匀度相对较低;6个断面水体共检测到真核浮游生物33个门、46个纲、60个目、71个科和100个属;隐藻类(Cryptomonadales)和纤毛门(Ciliophora)是FB外其他断面水体的主要优势物种,而FB主要优势物种为子囊菌门(Ascomycota);6个断面水体真核浮游生物群落组成均具一定差异,入海口LY的真核浮游生物群落组成与其他区域差异尤为明显;此外,水体真核浮游生物多样性与环境因子具有显著相关性,其中纤毛门(Ciliophora)与TN、NO_(2)^(-)-N和NO_(3)^(-)-N呈显著正相关,而隐藻类的Kathablepharidae属和环节动物门(Annelida)皆与COD_(Mn)呈显著正相关;HN和FB真核浮游生物的营养型和功能群落组成不同于其他断面水体,未定义腐生营养型微生物(Undefined Saprotroph)为二者特有的功能群落.

Eukaryotic plankton is an important part of the water ecosystem,and it plays vital roles in the material circulation,energy flow and information exchange of the water ecosystem.In order to explore the relationship between the characteristics of eukaryotic plankton diversity in Luoyang River,the representative water samples were collected at the six locations,including Houban Reservoir(HB),Huinyu Reservoir(HN),Fubin Street Bridge(FB),Frontdai and Backdai junction(FHD),Xingzhai Sluice(XZ)and Luoyang Bridge(LY)by means of illumina miseq high-throughput sequencing of 18 S rRNA genes and water quality monitoring technology.The results were as follows:the water quality of the HB and HN were better condition,and their water quality index categories were all above GradeⅡ;while the water quality of XZ and LY was inferior,except for individual water quality indicators above GradeⅡ,other indicators were below GradeⅢ.The composition of eukaryotic plankton in different water samples was different.The richness of species in HN was relatively high,and the species distribution was even,while the species richness and uniformity at LY was relatively low.There were eukaryotic plankton of 33 phylum,46 class,60 order,71 family and 100 genera detected in six water samples.Cryptomonadales and Ciliophora were dominant at the phylum level in the HB,HN,FHD,XZ and LY,while Ascomycota was dominant in the water of FB.The eukaryotic plankton compositions were various with locations,and that of LY at the estuarine area was distinctive from other regions particularly.In addition,the diversity of eukaryotic plankton in the six water samples has a significant correlation with environmental factors,among which,the main dominant species,Ciliophora,was significantly positively correlated with TN,NO_(2)^(-)-N and NO_(3)^(-)-N,while the Kathablepharidae and Annelida of Cryptomonadales were significantly positively correlated with COD_(Mn).The trophic and functional community composition of eukaryotic plankton in HN and FB were different from other water samples.Undefined Saprotroph was the unique functional community of both.