松花江浮游生物群落DNA指纹与物种组成比较研究

对2006年1月采自松花江红旗渡口到同江7个样点的浮游生物群落进行了RAPD指纹分析,进而探讨了河流生态系统浮游生物群落DNA指纹与物种组成之间的关系.筛选出的8条随机引物扩增的谱带全为多态性带,其中特有条带所占比例最大(30.2%);形态分类共检测到浮游生物66种,且没有检测到7个样点的共有种类;这些结果显示研究区域浮游生物群落相似性比较低,环境差异性较大.基于DNA指纹的聚类进一步表明,同江、红旗渡口和佳木斯的浮游生物群落较为相似而聚为一枝,哨口、肇源和哈尔滨为一枝,而松原成为单独的一枝.物种组成则将上游的红旗渡口与哨口,下游的同江与佳木斯分别划为一类,位于中间的3个样点为一类.DNA指纹主要揭示相对优势类群DNA的多态性,因此主要反映的是浮游生物群落与环境的关系;而物种组成在这里更多是反映与空间距离的关系,水流是重要的影响因素,上游的部分个体随水流带到了下游.由此可见,浮游生物群落DNA指纹分析在河流生态系统大空间尺度研究中具有重要意义,尤其是在揭示群落与环境关系方面,并能为水环境分子生物学评价体系的建立积累基础资料和提供蘑要依据.图4表3参21

DNA Fingerprinting and Species Composition of the Plankton Communities in the Songhuajiang River,China

DNA polymorphism of the plankton communities from the Songhuajiang River, China was investigated by random amplified polymorphic DNA (RAPD), and the relationship between DNA fingerprinting and species composition was explored then. All the detected bands were polymorphic, and the individual bands accounted for 30.2%. Totally, 66 plankton species were detected by morphological identification, and no common species was found. These results indicated that there may be some significant differences among the investigated plankton communities, which were determined by their environmental discrepancies. Based on the DNA fingerprinting, three main groups of plankton communities were identified by UPGMA clustering. Group one consisted of Tongjiang (TJ), Hongqi (HQ) and Jiamusi (JS); group 2 contained Shaokou (SK), Zhaoyuan (ZY) and Harbin (HB); and group 3 comprised only Songyuan (SY). When using the data of species composition, the plankton community from HQ was most similar to that from SK; TJ was most similar to JS; and the other three sites comprised one group. In fact, the DNA fingerprinting of the target community was biased toward those species occurring with relatively high abundance. Therefore, it mainly reflected the relationship between the community and environment. Because river flow randomly brought some plankton organisms from upstream to downstream, the qualitative analysis of the species composition could mainly reflect the spatial distribution of the sampling sites. DNA fingerprinting of the plankton communities can play an increasingly important role in studying the relationship between each community and its environment, and provide useful information for the aquatic environment assessment. Fig 4, Tab 3, Ref 21