5个罗非鱼群体的遗传分析与分子标记

Genetic analysis and molecular marker of five tilapia populations

采用经过筛选的 15条随机引物对奥利亚罗非鱼Oreochromisaureus(Au) 和 4个尼罗罗非鱼群体Oreochromisniloticus即尼罗美国群体Ⅰ (AnⅠ)、美国群体Ⅱ (AnⅡ)、美国群体Ⅲ (AnⅢ )、“吉富”群体 (GF) 进行RAPD分析。结果发现: 1 ) 各罗非鱼群体内的平均遗传相似度依次为Au(0 9236)、AnⅠ (0 8158)、AnⅡ (0 7813)、AnⅢ (0 7853)、GF (0 7458); Au与AnⅠ、AnⅡ、AnⅢ及GF的种群间平均遗传距离分别为 0 3154、0 2755、0 2685和 0 2392。2) 用引物S509、S506、S471扩增出具有群体特异性的带, 其中用S509扩增的 1 600bp、2 000bp两片段为 4个尼罗群体所特有, 可作为区别Au的分子标记; 用S506扩增的 2 000bp片段为AnⅠ、AnⅡ、GF所特有, 可以作为与AnⅢ区别的分子标记; 用S471扩增的 150bp片段为AnⅡ所特有, 可作为区别GF和AnⅠ的分子标记。

The genetic variations among 5 tilapia populations including Oreochromis aureus(population Au) and Oreochromis niloticus(population AnⅠ, AnⅡ, AnⅢ and GF) were evaluated by randomly amplified polymorphic DNA (RAPD). Fifteen primers revealed that: (1) The average genetic similarity index of the populations ranked as Au (0.9236),AnⅠ(0.8158),AnⅡ(0.7813),AnⅢ(0.7853),GF(0.7458). Inter-specific genetic distances between O.aureus and the other four populations of O.niloticus were 0.3154, (0.2755), 0.2685,0.2392, respectively; and (2) Distinctive bands were amplified by primer S509,S506 and S471. The 1600 bp and 2 000 bp bands amplified by primer S509 occurred only in 4 populations of O.niloticus and could be used as molecular markers to identify O.niloticus and O. aureus. The 2 000 bp band amplified by primer S506 found only in population AnⅠ,AnⅡ and GF, could identify AnⅢ. The 150 bp band amplified by primer S471 in AnⅡ could distinguish from AnⅠ and GF.