橙色莫桑比克罗非鱼和荷那龙罗非鱼的AFLP分析

AFLP Analysis of Two Species of Tilapia,O.mossambicus and O.hornorum

运用AFLP分子标记技术检测了橙色莫桑比克罗非鱼(Oreochromis mossambicus)和荷那龙罗非鱼(Oreochromishornorum)的种群遗传多样性。提取2种鱼的基因组DNA,经EcoRⅠ和MseⅠ限制性内切酶酶切并加接头,从16对选扩引物组合中选出3对扩增结果较好的引物进行PCR扩增。扩增产物经PAGE胶电泳、银染,检测其多态性。3对引物在2种罗非鱼的40个个体中共扩增出94条带,其中多态性条带76条,占总扩增条带的80.9%,2个群体的多态性条带比例分别为71.6%和52.4%。根据Nei氏(1978)统计分析得出橙色莫桑比克罗非鱼种群内遗传相似系数为0.765,荷那龙罗非鱼的为0.821,表明2个罗非鱼种群均具有较高的遗传多样性,橙色莫桑比克罗非鱼种群内遗传多样性相对更高些。2种罗非鱼的种间遗传距离为0.279,推测该杂交组合可能具有杂种优势。

The genetic polymorphism of Oreochromis mossambicus and Oreochromis-hornorum were analyzed by AFLP （amplified fragments length polymorphism）. The genomic DNAs were digested by two restriction enzymes： EcoR Ⅰ and Mse Ⅰ . The digested genomic DNA was ligated with the adapters and then amplified. Three selective amplification primer combinations selected from 16 primer combinations were chosen for formal amplification. The PCR products were analyzed by PAGE and silver-stained. A total of 94 bands were detectel, 76 of which were polymorphic （81. 4%） in 40 samples; the percentages of polymorphic bands of O. rnossambicus and O. hornorurn were 71.6 % and 52.4%, respectively. The Nei genetic similarities were 0. 765 in O. rnossarnbicus and 0. 821 in O. hornorurn, which showed that there was high genetic polymorphism in the two tilapias, and that of O. rnossarnbicus was higher comparatively. The value of inter-specific genetic distance was 0. 279, which indicated that there would be heterosis in the hybrid offspring.