高动态鄱阳湖水体中水华蓝藻种源追溯及水华迁移扩散机制研究

Increasing eutrophication in lake have led to frequent occurrence and spreading of cyanobacterial blooms in global regions. However, it is unclear how cyanobacterial blooms occur, transport and spread in an open water with high dynamics. The present study, targeting the Poyang lake with seasonal water level fluctuation, will largely perform field investigation on cyanobacterial populations and limnological survey, and examine community structure, genetic diversity and phylogenetic relationship of water bloom forming cyanobacteria in the different regions of the lake and its surrounding waters, to explore the origin for the occurrence of these cyanobacteria and the trend of cyanobacterial population dynamics and cyanobacterial transport path and degrading mechanism in the lake. Through the experiments under environmental stress and competition between strains, the dynamics of the genotypes of the bloom forming cyanobacteria and their association with environmental factors will be discussed, which will further elucidate the mechanisms for dominance and trend of cyanobacterial populations. Such results will help to understand how cyanobacterial blooms occur and maintain in open and flow waters with highly varied water levels and high turbidities like Poyang lake, further providing the basis for prediction and warning of cyanobacterial blooms in these waters.

蓝藻水华是全球性的生态灾害现象，在高浊度和高水位变化的流动水体中也时常发生。然而，对高动态水域中蓝藻水华的发生种源、水华的迁移扩散和消退机制等问题的研究还不深入。本项目以鄱阳湖为例，针对鄱阳湖高水位变化、高流速、高浑浊度的开放式生态环境特征，通过对流域水华蓝藻种群和湖沼学调查，分析研究鄱阳湖各破碎化湖区以及外源水域中水华蓝藻的群落结构、遗传多样性及系统发育关系，揭示鄱阳湖水华蓝藻潜在的内外源性种质来源、种群动态趋势及种群扩散路径和消退机制；通过遗传分析、竞争实验等实验手段从分子水平解释鄱阳湖水华蓝藻种群的来源模式、种群优势度形成及维持机制，这对鄱阳湖及其类似湖泊水系的蓝藻水华监测和预警研究具有重要意义。

蓝藻水华是全球性的生态灾害现象，在高浊度和高水位变化的流动水体中也时常发生。然而，对高动态水域中蓝藻水华的发生种源、水华的迁移扩散和消退机制等问题的研究还不深入。本课题我们于2016年1月至2017年11月间，针对鄱阳湖开展水体富营养化、浮游植物多样性、微囊藻时空分布，产毒分型及种内遗传多样性进行了研究，并做了鄱阳湖长孢藻多样性和有色可溶有机物的调查。针对鄱阳湖高水位变化、高流速、高浑浊度的开放式生态环境特征，通过对流域水华蓝藻种群和湖沼学调查，分析研究鄱阳湖各破碎化湖区以及外源水域中水华蓝藻的群落结构、遗传多样性及系统发育关系，揭示鄱阳湖水华蓝藻潜在的内外源性种质来源、种群动态趋势及种群扩散路径和消退机制；通过遗传分析、竞争实验等实验手段从分子水平解释鄱阳湖水华蓝藻种群的来源模式、种群优势度形成及维持机制，这对鄱阳湖及其类似湖泊水系的蓝藻水华监测和预警研究具有重要意义。