摘要
以长江、通江湖泊(洞庭湖、鄱阳湖)、陆封型湖泊(牛山湖、涨度湖、汤逊湖、肖四海湖)不同水体鳜为研究材料,利用微卫星遗传标记对其种群遗传结构进行分析,结果表明:由期望杂合度(He)和多态信息含量指数(PIC)检测的遗传多样性由大到小的顺序为:长江、通江湖泊群体>无放流陆封型湖泊群体>放流的陆封型湖泊群体,并且发现一些稀有等位基因位点在陆封型湖泊鳜群体中消失;由杂合度检验可以看出,所有群体在绝大多数位点都呈现杂合过剩现象,经过哈代-温伯格平衡检验,显示均显著偏离哈代-温伯格平衡(P<0.001),属于连锁不平衡群体;根据遗传距离构建的UPGMA聚类图,鳜群体被分成三支,长江、通江湖泊聚类为一支,无放流陆封型湖泊与放流陆封型湖泊亦分为两支。群体间Fst为0.2727,显示群体间已发生较大遗传分化,其变异主要体现在通江湖泊和陆封型湖泊之间,同时由于陆封型湖泊之间放流管理模式的不同,亦会产生中度分化。研究结果表明,江湖阻隔是造成定居性鱼类鳜种群间遗传分化的重要原因之一。
The sinipercine fishes,belong to a group of the lower percoids,have a geographical distribution in East Asia and dwell in lakes and rivers system,of which most species are in China.The mandarin fish(Siniperca chuatsi) is a very popular food in China.It has become one of the important aquaculture species and there is considerable expertise in its culture.The aim of this study was to explore the relationship between environment and the genetic background of S.chuatsi populations and their genetic differentiation,thus provided information and theoretical basis for artificial releasing in a large area,also in the development and utilization of germplasm resources of S.chuatsi.Ten Simple Sequence Repeat(SSR) markers were used to compare genetic diversity among seven S.chuatsi populations which were consisted of Yangtze Rive,Yangtze River-connected lakes(Dongting Lake and Poyang Lake);Yangtze River-disconnected lakes with stocking(Tangxun Lake,Zhangdu Lake and Niushan Lake) and Yangtze River-disconnected lake without stocking(Xiao-Sihai Lake),all samples collected on the fishing boat directly.Observed heterozygosity(Ho),expected heterozygosity(He) values,polymorphic information(PIC) and number of effective alleles(Ne) were all determined.The results showed that S.chuatsi has a certain genetic diversity although some rare polymorphic loci were missing.The observed genetic diversity was in the order:Yangtze River,Yangtze River-connected lakesYangtze River-disconnected lakes without stocking Yangtze River-disconnected lakes with stocking.In the study,some rare alleles were found disappeared in Yangtze River-disconnected lakes.157 alleles were found in the 7 populations by using 10 primers,the number of alleles in populations of XSH,NS,ZD,TX,YZ,DT and PY was 37,32,29,25,62,67 and 76,respectively.The PIC values among 7 populations varied from 0.4240 to 0.7322.At the same time,the lowest values was found in TX population while the higher values were found in Yangtze River,Yangtze River-connected lakes(DT and PY populations),the values were 0.7002,0.6907 and 0.7322 respectively.This result suggested that as artificial interference pressures increased,the change of genetic diversity decreased.After it being checked by χ2 test of the Hardy-Weinberg equilibrium(HWE),most loci were found to be significantly deviated from HWE(P〈0.001) among the 7 populations in which heterozygote excess was apparent.The genetic similarity coefficient and Nei's standard genetic distance were computed based on the allele frequencies.Genetic differentiation and hierarchical partition of genetic diversity were evaluated by Fst and Nm.The genetic differentiation coefficient among the population(Fst) was 0.2727,which showed small partial genetic diversity(27.27 %) present among populations.Gene flow(Nm) between primers varied from 0.4677 to 0.9467 and the mean Gene flow(Nm) was 0.6669.The results showed geographic isolation as the main reason for genetic differences between Yangtze River-connected lakes and disconnected lakes.The UPGMA cluster figure that was constructed based on the genetic distance matrix showed seven populations that became genetically closer at each step.The first group was the YZ and PY populations and the closed together with DT(Yangtze Rive,Yangtze River-connected lakes) population,group two consisted of the XSH population and the NS population,group three was the ZD and TX populations.Analysis also showed that genetic diversity in non-stocking population was higher than those of stocking populations,which indicated that artificial releasing also resulted in genetic differentiation.The results of the study have important implications for the stock management of S.chuatsi populations in shallow lakes along the middle reaches of the Yangtze River.
出处
《水生生物学报》
CAS
CSCD
北大核心
2010年第4期843-850,共8页
Acta Hydrobiologica Sinica
基金
国家自然科学基金重点项目(30830025)资助
关键词
鳜
地理种群
微卫星
遗传结构
Siniperca chuatsi
Geographic population
Microsatellite
Genetic structure