胡子鲇3个养殖群体遗传结构的AFLP分析

Analysis on Genetic Structure of Three Cultured Populations Claris fuscu with AFLP Markers

应用AFLP方法,从64对引物中筛选出5对用于分析胡子鲇(Claris fuscus)厦门(XM)、江门(JM)、玉林(YL)等3个养殖群体共90个个体群体内、群体间遗传多样性。扩增共得到289条清晰谱带,引物多态性介于47.8%～63.8%,平均多态性比率为56.4%。胡子鲇群体总遗传杂合度(Ht)、遗传分化系数(Hs)、遗传分化度(Gst)和基因流(Nm)分别为0.161 1、0.153 6、0.051 1和8.501 8,表明胡子鲇多态性处于中等偏下水平,群体内部遗传分化系数较高,三个群体间无较大分化,群体间基因流动较好。其中,JM群体多态性比率、有效等位基因数Ne、Nei’s指数和Shannon指数都较XM群体和YL群体高,种内分化程度较好。对群体进行两两比较发现,XM群体和YL群体间分化程度最大,XM群体和JM群体次之,JM群体和YL群体最小。基于杂交优势,推断XM和YL群体繁殖所产生的后代将具有比亲代更为优良的性状。

Genetic diversities of 90 individuals （30 each population） from three cultured populations of Xiamen （XM）, Jiangmen （JM） and Yulin （YL） were analyzed. 5 from 64 primer-combinations displayed a total of 289 AFLP loci. The percentage of polymorphic loci was from 47.8% to 63.8%, and averaged 56.4%. The average total genetic diversity （Ht）, the average genetic diversity within populations （Hs）, the gene differentiation coefficient （G^0, and the gene flow index （Nm） was 0.161 1, 0.153 6, 0.051 1 and 8.501 8, respectively. Results showed that the gene diversity index of C. fuscus was in lower middle level, and the genetic variation mainly came from individuals within populations but not between geographic populations. Compared with the population XM and YL, population JMdisplayed better polymorphic, higher effective number of alleles, Nei＇s gene diversity and Shannon genetic diversity index. Among the 3 cultured populations, the largest differentiation was displayed between population XM and YL, then between XM and JM, and the smallest between JM and YL. Results suggested that hybridization of population XM and YL could produce descendants with better characters.