微卫星标记分析罗非鱼群体的遗传潜力

Genetic potential analysis of six Tilapia populations by microsatellite DNA markers

利用25个微卫星标记,对奥利亚罗非鱼2个群体[＂夏奥1号＂（ZA）、广西群体（GA）]和尼罗罗非鱼4个群体[埃及品系（ZN）、88品系（XN）、广西群体（GN）、美国品系（MN）]进行检测。共检测到7 775个扩增片段,长度在100~400 bp;等位基因数3~8个不等,共计143个等位基因;平均每个基因座扩增得到5.72个等位基因。各群体平均观测杂合度（H o）在0.7253~0.8160之间,平均期望杂合度（He）在0.5146~0.6834之间,平均多态信息含量（PIC）在0.4212~0.6105之间,平均有效等位基因数（A e）在2.20~3.23之间。ZA与GA遗传相似系数最高（0.9130）,ZA与ZN遗传相似系数最低（0.4352）。总的说来,4个尼罗罗非鱼群体的遗传潜力较高,2个奥利亚罗非鱼群体的遗传潜力适中。

Twenty five microsatellite loci were used to analyze two blue tilapia populations [＂Xia’ao 1＂（ZA）,Guangxi population] and four nile tilapia populations [Egypt strain（ZN）,88 strain（XN）,Guangxi population（GN）,American strain（MN）].A total of 7775 fragments ranging from 100 bp to 400 bp in length were obtained.Three to eight alleles were ampli-fied in 25 loci and 143 alleles in all the six populations.The average number of alleles in each locus was 5.72.The average values of observed heterozygosity（Ho） ranged from 0.7253 to 0.8160,the average expected heterozygosity（He） ranged from 0.5146 to 0.6834,the average polymorphic information content（PIC） ranged from 0.4212 to 0.6105,and the number of average effective alleles（A e） ranged from 2.20 to 3.23.The highest genetic similarity index was 0.9130（between ZA and GA）;and the lowest was 0.4352（between ZA and ZN）.The results showed that the four nile tilapia populations con-tained a high level of genetic potential,and the two blue tilapia populations were moderate.