太湖蓝藻多样性及群落结构时空动态研究

发布时间：2018-05-12 19:19

本文选题：太湖 + 富营养化　；参考：《华东理工大学》2016年硕士论文

【摘要】：太湖流域工农业的快速发展、几十年的过量营养输入使得湖泊富营养化严重,伴随着连年的蓝藻水华出现,己严重制约流域社会经济的可持续发展。目前关于太湖蓝藻水华的研究多关注某一季节(通常是夏季)或某一特定地点(如梅梁湾)的某一蓝藻属(微囊藻属)的多样性或丰度,很少有关于太湖蓝藻水华的系统研究以分析蓝藻群落结构随季节和空间变化的动态变化规律。为了系统了解太湖水体中蓝藻的多样性和群落结构的时空动态,本课题选取太湖五个不同湖区(东太湖、南部沿岸区、西部沿岸区、竺山湖和梅梁湾)作为采样点采集一年的水样,并参照国家标准测定水样理化参数。利用变形梯度凝胶电泳(DGGE)技术对太湖不同时间(一、三、六、九月份)和不同地点蓝藻的多样性和群落结构变迁进行分析,同时结合主成分分析(PCA)和冗余分析(RDA)分析蓝藻群落结构与环境因子的相关性。DGGE分析结果表明太湖不同季节和不同湖区的优势蓝藻均为微囊藻属(Microcystis)、聚球藻属(Synechococcus)和蓝菌属(Cyanobium),其中Microcystis口Synechococcus占统治地位。Synechococcus的多样性高于Microcystis,但相对丰度低于后者。Microcystis在冬春季节的东太湖和南部沿岸区相对丰度较高,而在夏秋季节的其它三个湖区相对丰度较高,说明夏秋季节的蓝藻水华不只与冬春季节水体中的蓝藻丰度有关。两种超微蓝藻(Cyanobium和Synechococcus)在太湖中处于优势地位,但是之前关于太湖蓝藻的研究很少关注超微蓝藻暴发水华的可能性。富营养化湖泊中普遍存在着三种潜在的微囊藻素生产者微囊藻属(Microcystis)、项圈藻属(Anabaena)和浮丝藻属(Planktothrix)。由于Anabaena是冬春季节的优势蓝藻,但在夏秋季节水体中并未出现,从冬到夏,Anabaena逐渐被其它优势蓝藻(如Microcystis)取代；而Planktothrix在四个研究月份中均未出现,因此Microcystis是太湖蓝藻水华期仅有的潜在的微囊藻素生产者。梅梁湾的叶绿素-a浓度(蓝藻丰度)高于西部沿岸区和竺山湖,发生蓝藻水华暴发的几率最大,但是其它理化参数(如溶解氧、总氮和高锰酸盐指数等)的时空变化规律显示梅梁湾的富营养化水平低于竺山湖和西部沿岸区。表明蓝藻水华不仅与富营养化水平有关,还与此地的风向和地理位置等相关。RDA结果表明,与一、三月份水样蓝藻群落结构显著相关的环境因子是硝酸盐氮、高锰酸盐指数和氨氮,而与六、九月份水样显著相关的环境因子则是水温。因此限制太湖的氮和碳输入会是控制太湖蓝藻生长并最终控制蓝藻水华的关键。本研究结果有利于建立优良的蓝藻水华检测机制以及推测水华暴发后的走向,为蓝藻水华的预防和治理提供理论参考。
[Abstract]:With the rapid development of industry and agriculture in Taihu Lake Basin, the eutrophication of the lake has been seriously caused by the excessive nutrient input for several decades. With the emergence of cyanobacteria Shui Hua in successive years, the sustainable development of social economy in the basin has been seriously restricted. Current studies on cyanobacteria Shui Hua in Taihu Lake have focused on the diversity or abundance of a cyanobacteria (Microcystis) in a particular season (usually in summer) or in a particular place (such as Meiliang Bay). There are few systematic studies on cyanobacteria Shui Hua in Taihu Lake to analyze the dynamic changes of the community structure with seasonal and spatial changes. In order to systematically understand the diversity of cyanobacteria and the temporal and spatial dynamics of community structure in Taihu Lake, five different lakes of Taihu Lake (East Taihu Lake, Southern Coastal area, Western Coastal region) were selected. Zhushan Lake and Meiliang Bay) were used as sampling sites to collect water samples for one year, and the physical and chemical parameters of water samples were determined with reference to national standards. The diversity and community structure changes of cyanobacteria at different times (January, March, June, September) and different locations in Taihu Lake were analyzed by using deformed gradient gel electrophoresis (DGGE) technique. DGGE analysis showed that the dominant cyanobacteria in Taihu Lake in different seasons and different lakes are Microcystis microcystis, Synechococcus (Synechococcus) and cyanobacteria. The diversity of Synechococcus at the mouth of Microcystis is higher than that of Microcystis, but the relative abundance is lower than that of Microcystis. The relative abundance of the other three lakes in the summer and autumn seasons is relatively high, which indicates that the cyanobacteria Shui Hua in the summer and autumn seasons is not only related to the abundance of cyanobacteria in the water in winter and spring seasons. Two species of Cyanobium and Synechococcus are dominant in Taihu Lake, but previous studies on cyanobacteria in Lake Taihu have paid little attention to the possibility of Shui Hua outbreak. There are three kinds of potential microcystis in eutrophic lakes, Microcystis, Anabaena and Planktothrixus. Since Anabaena is the dominant cyanobacteria in winter and spring, it is not found in the summer and autumn seasons. From winter to summer, Anabaena is gradually replaced by other dominant cyanobacteria (such as Microcystis), but Planktothrix does not appear in the four months of study. Therefore, Microcystis is the only potential microcystin producer in Shui Hua stage of cyanobacteria in Taihu Lake. The concentrations of chlorophyll a (abundance of cyanobacteria) in Meiliang Bay were higher than those in western coastal area and Zhushan Lake, and the incidence of cyanobacteria Shui Hua outbreak was the highest, but other physical and chemical parameters such as dissolved oxygen (do) were found in Meiliang Bay. The temporal and spatial variations of total nitrogen and permanganate index show that the eutrophication level of Meiliang Bay is lower than that of Zhushan Lake and western coastal area. The results showed that Shui Hua was not only related to eutrophication level, but also to the wind direction and geographical location of the area. The results showed that the environmental factor significantly related to the community structure of cyanobacteria in March was nitrate nitrogen. The permanganate index and ammonia nitrogen, and the environmental factors significantly related to the water samples in June and September are water temperature. Therefore, limiting the input of nitrogen and carbon will be the key to control the growth of cyanobacteria and ultimately control the Shui Hua of cyanobacteria in Taihu Lake. The results of this study are helpful to establish an excellent Shui Hua detection mechanism of cyanobacteria and to speculate on the trend of Shui Hua outbreak, and to provide a theoretical reference for the prevention and treatment of cyanobacteria Shui Hua.
【学位授予单位】：华东理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：X524

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