东湖螅状独缩虫(纤毛门：寡膜纲)的异质性

以螅状独缩虫（Carchesium polypinum Linne,1785）为研究对象,利用RAPD技术对武汉市南湖、沙湖和东湖3个湖区的螅状独缩虫样本进行了DNA多态性比较分析,以确认种群并期望促进微型生物种群生态学研究.结果如下：（1）从120条随机引物中筛选到31条有清晰扩增条带的,其中20条引物扩增出172条条带清晰、多态性高的条带,片段大小为100～1600bp,而其余11个引物扩增出59条相对多态性差的清晰条带,片段大小为100～1500bp;（2）扩增产物经SPSS12.0与RAPDistance 1.04分析显示,东湖世纪钟（Z）、水果湖（H）和南湖（N）3个样点构成一个分支,而东湖风光村样点（F）或独自形成一支,或与沙湖样点（S）构成相对的姊妹分支.东湖3个样点样本被其它湖泊样本所分隔,表明：东湖水体中螅状独缩虫个体集合为多个种群.这一发现不仅将推动同一水体中微型生物种群生态学研究,更有意义的是可启动关于水体微型生物种群间过渡区本质及物种扩散行为的研究,以期为阐明种群分化和物种形成的机制积累基础资料.

Heterogeneity of Carchesium polypinum(Ciliophora: Peritrichida)in Donghu Lake

Population biology,which has been mainly studing the terrestrial animals and plants,is an important branch of ecology.During these years,there are some researches extending to the hydrobiont populations,such as fish and shrimp populations and get many interesting results.However,because of the ambiguity of the definition of micro-hydrobiological populations and some hypotheses hold that all individuals of species in a lake belong to one population and free living species are cosmopolitan,the researches in this area lagged behind that of terrestrial populations;the studies of micro-hydrobiological population are rare in literature.In this research RAPD has been used to study the genetic diversity of Carchesium polypinum populations that have been sampled from three lakes that include Lake Donghu(D),Lake Nanhu(N) and Lake Shahu(S).The procured results have been used to deduce the definition of the C.polypinum populations.We used 120 arbitrary primers to amplify the DNA extracted from the five C.polypinum samples and from this 31 primers resulted in giving out positive bands.The result were as followed:(1) the 20 primers produced 172 clear bands with an average of 8.6 fragments,ranging from 100bp to 1600bp,.The other 11 primers produced 59 legible bands in an average of 5.4 fragments that ranged from 100bp to 1500bp;(2) Results of SPSS 12.0 and RAPDistance 1.04 that had similar trees were composed of two parallel main branches.Samples from Shijizhong(Z) of D,Shuiguohu(H) of D and N clustered into a branch and another sample from D-Fengguangcun(F) gathered with S or itself made another main branch.The result that the three samples of D were separated by the samples of other lakes suggested that the individuals of C.polypinum in D belong to several populations.This discovery will promote the population ecology researches of micro-hydrobiont,moreover,it will help study the essence of its transitional zone and the behavior of dispersal and vicaricance.This report can dedicate to the investigations of population differentiation and the mechanism of speciation.