基于eDNA的硅藻群落时空异质性及生态健康评价  

Spatial and Temporal Heterogeneity and Ecological Health Evaluation of Diatom Community Based on eDNA

作　　者：姜山 张颜 李飞龙 张效伟[1,2] JIANG Shan;ZHANG Yan;LI Fei-long;ZHANG Xiao-wei(State Key Laboratory of Pollution Control&Resource Reuse,School of Environment,Nanjing University,Nanjing 210023,China;Jiangsu Key Laboratory of Chemical Safety and Health Risk of Eco-Environmental Protection,Nanjing 210023,China)

机构地区：[1]南京大学环境学院,污染控制与资源化国家重点实验室,南京210023 [2]江苏省生态环境保护化学品安全与健康风险研究重点实验室,南京210023

出　　处：《环境科学》2023年第1期272-281,共10页Environmental Science

基　　金：国家重点研发计划项目(2021YFC3201003);江苏省环保科研课题项目(2021002)。

摘　　要：近年来,环境DNA技术广泛应用于水生态生物多样性监测,如何基于环境DNA数据建立河流生态健康评价方法是当前研究的热点.拟开发基于环境DNA的分子硅藻指数来指示人类活动影响下的河流生态健康状况.首先通过环境DNA技术监测了沙颍河流域春秋两季硅藻群落组成和结构变化,解析了春、秋两季群落的驱动环境因子;进一步比较了4种基于环境DNA宏条形码数据的计算策略(OTU-分类、OTU-无分类、ASV-分类和ASV-无分类),构建了适合于评估沙颍河流域生态健康状况的分子硅藻指数.结果表明:(1)硅藻群落结构存在季节性差异,其中Discostella pseudostelligera、Nitzschia amphibia和Diatoma vulgaris等类群是区分春、秋季硅藻群落季节差异的主要因素;(2)重金属Mn、Fe和TN(总氮)是影响春季硅藻群落结构变化的主要环境因子,COD和Cu是影响秋季硅藻群落结构变化的主要环境因子;(3)在4种计算策略中,基于OTU-无分类数据计算的硅藻指数更好地反映了环境梯度变化;硅藻指数显示,沙颍河流域生态健康状况在时间上秋季优于春季,而在空间上上游优于下游.综上,通过eDNA技术监测了沙颍河春、秋两季硅藻群落,构建了沙颍河流域分子硅藻指数,促进了环境DNA技术在河流生态健康评价中的应用.In recent years,environmental DNA(eDNA)has been widely used in aquatic biodiversity monitoring,and how to establish a river ecological health assessment method based on eDNA has become a hot topic.This study was intended to develop a molecular diatom index based on eDNA to indicate the ecological health status of rivers under the influence of human activities.Firstly,the diatom community composition and structural changes in the Shaying River basin in spring and autumn were monitored through eDNA,and the driving environmental factors of the diatom community were diagnosed.Further,four strategies(OTU-taxonomy,OTU-free,ASV-taxonomy,and ASV-free)based on eDNA metabarcoding data were compared,and a molecular diatom index suitable for ecological health assessment in the Shaying River basin was constructed.The results showed that:(1)there were seasonal differences in diatom community structure,and Discostella pseudostelligera,Nitzschia amphibia,Diatoma vulgaris,and other groups were the main factors to distinguish the seasonal differences.(2)Mn,Fe,and TN were the main environmental factors affecting diatom community structure in spring,whereas COD and Cu were the main environmental factors affecting diatom community structure in autumn.(3)Among the four strategies,the diatom index calculated based on OTU-free data better reflected the environmental gradient change;the diatom index showed that the ecological health status of the Shaying River Basin was better in autumn than that in spring in time and better in the upstream than that in the downstream in space.In conclusion,this study monitored diatom community in Shaying River in spring and autumn through eDNA and constructed the molecular diatom index in the Shaying River basin,which promoted the application of eDNA to evaluate river ecological health.

关 键 词：环境DNA(eDNA) 硅藻指数 无分类数据 河流生态健康 生物多样性 

分 类 号：X171[环境科学与工程—环境科学] X826