吉丽罗非鱼(尼罗罗非鱼♀×萨罗罗非鱼♂)及其两亲本遗传变异的微卫星分析

The Genetic Variation Analysis of Microsatellite among the Gili Tilapia (Oreochromis niloticus ♀×Sarotherodon melanotheron♂) and Its Parents

吉丽罗非鱼是由耐盐性较强的萨罗罗非鱼做父本与生长速度较快的尼罗罗非鱼做母本进行杂交、杂交后代自交产生,2009年全国水产原良种审定委员会审定为养殖新品种。为了分析吉丽罗非鱼及其两亲本遗传特性,选择有代表性的6对微卫星引物,对这3种罗非鱼遗传变异进行研究分析。研究结果表明:(1)6对微卫星引物扩增产物片段大小为180～350bp,共发现21个等位基因,鱼类群体间、微卫星座位间及等位基因间都存在极显著差异。(2)有效等位基因数(Ne)、Nei's基因多样指数(H)和多态信息含量(PIC)值等群体遗传多样性指标都是吉丽罗非鱼>尼罗罗非鱼>萨罗罗非鱼,吉丽罗非鱼PIC值达到了0.657,属于高度多态性。(3)吉丽罗非鱼与萨罗罗非鱼的遗传距离要比与尼罗罗非鱼的近,萨罗罗非鱼对吉丽罗非鱼的遗传影响要大于尼罗罗非鱼。

Gili tilapia, a F2 hybrid offspring by Oreochromis niloticus （♀）× Sarotherodon melanotheron （♂）, had been examined and approved by the China National Aquaculture Variety Approval Committee as a new variety for aquaculture in 2009. S.melanotheron showed stronger salt-tolerance while O.niloticus presented faster growth rate. Six pairs of microsatellite primers were chosen to analyze the genetic characteristics of Gili tilapia and its parents. The results were shown as follows： （1） The sizes of the product amplified by the six microsatellite primer pairs was ranged from 180 to 350 bp. A total of 21 alleles were found and significant difference was observed among the groups, microsatellite loci and alleles; （2） The value of effective allele number （Ne）, Nei’s gene diversity index （H） and polymorphic information content rankings （PIC） were Gili tilapia＆gt;O.niloticus＆gt;S.melanotheron. Gili tilapia showed a highly polymorphic and the PIC value was 0.657. （3） The genetic distance between Gili tilapia and S.melanotheron was closer than that of Gili tilapia and O.niloticus, which showed S.melanotheron had more important inflencence on Gili tilapia than O.niloticus.