利用RAPD-PCR与ISSR-PCR标记技术分析长江口刀鲚的群体遗传结构

利用RAPD-PCR及ISSR-PCR两种分子标记技术对长江出海口两年3个群体的52条刀鲚（Goiliaectenes）进行群体遗传结构的分析。在3个群体中，利用RAPD-PCR标记技术，15个10bp随机引物共检测到110条带，多态性为0．490～0．657，Shannon多样性指数为18．63～22．38，Nei平均遗传距离为0．1195～0．1454；而利用11个ISSR引物所获得的相应结果分别为67、0．576～0．682、11．56～13．66以及0．117～0．147。相关性分析表明这两种技术所获得的上述数据呈正相关（r=0．95，P〈0．05）。AMOVA结果显示，3个群体按采集时间划分成的两年之间的遗传变异不超过总变异的1．1％，同一年内群体间的遗传变异也分别只占总变异的6．99％（RAPD）和2．75％（ISSR-PCR），群体内各个体之间的遗传变异占总变异的96％（P〈0．0001），说明两年内所采集的3个群体之间基本上没有产生遗传分化。基于样品之间的Nei遗传距离所构建的Neighborjohing聚类图也清楚地显示出没有按采样的时间产生群体的遗传分化。对各样品之间的Nei遗传距离及Neighbor-joining聚类图分别经Mantel检测及支序分析，发现ISSR-PCR技术所获得的结果与RAPD-PCR技术的结果不存在明显的正相关，但ISSR-PCR标记技术具有在待测样品中能检测到高多态性等优点。

Population genetic structure of Coilia ectenes sampled from Yangtze River estuary revealed by RAPD-PCR and ISSR-PCR markers

Population genetic structure and genetic diversity of three populations of Coilia ectenes sampled from Yangtze River from 2002 to 2003 were revealed by RAPD-PCR and ISSR-PCR markers.There were 110 bands occurring in the three populations assayed by RAPD-PCR with fifteen 10-base primers,and the polymorphism was from 0.490 to 0.657,Shannon diversity index was from 18.63 to 22.38,and mean Nei's genetic distance was from(0.1195) to 0.1454.In the meanwhile,there were 67 bands occurring in the three populations revealed by ISSR-PCR with 11 primers,and the polymorphism was from 0.576 to 0.682,Shannon diversity index was from 11.56 to(13.66),and mean Nei's genetic distance was from 0.1169 to 0.1467.These data respectively from the two markers were significantly positively correlated(r=0.95,P<0.05).AMOVA analysis showed that the genetic variation between sampling years of the three populations accounted for less than 1.1% of the total one,while this variation between populations sampled in one year accounted for 6.99% revealed by RAPD-PCR or 2.75% by ISSR-PCR of the total one.It also showed that the genetic variation among samples within a population was the principal component,which accounted for more than 96% of the total one at P<0.000 1 assayed by the both markers.AMOVA results suggested that there was no significantly genetic diversity among the three populations of(C.ectenes),and this was confirmed by Neighbor-joining dendrogram constructed based on matrices of pairwise(Nei's) genetic distances among samples.Although the pairwise Nei's genetic distances among samples and the Neighbor-joining dendrogram from RAPD-PCR was not positively correlated with those from ISSR-PCR according to the Mantel test and the cluster analysis respectively,ISSR-PCR could reveal higher polymorphism in the tested populations.