4种裸胸鳝的分子遗传多样性和亲缘关系的RAPD分析

RAPD analysis of molecular genetic diversity and genetic relationship of four Gymnothorax species

采用29个随机引物,对海南近海及西沙的野生群体黄边裸胸鳝(Gymnothorax flavimarginatus)、云纹裸胸鳝(Gym-nothorax chilospilus)、波纹裸胸鳝(Gymnothorax undulatus)及细斑裸胸鳝(Gymnothorax fimbriatus)的基因组DNA进行了RAPD分析,并用UPGMA法对这4种裸胸鳝进行聚类分析。研究结果表明:(1)黄边裸胸鳝、云纹裸胸鳝、波纹裸胸鳝及细斑裸胸鳝4种裸胸鳝群体内遗传多样性都较高,其多态位点比率分别为68.65%、57.00%、50.80%、67.42%,平均杂合度分别为0.222 1%、0.207 4%、0.166 6%、0.221 2%,表明南海野生裸胸鳝遗传变异水平较高,种质资源状况良好;(2)4种裸胸鳝种间遗传距离及聚类分析表明,黄边裸胸鳝与细斑裸胸鳝遗传距离最近(0.340 6);黄边裸胸鳝与云纹裸胸鳝的次之(0.386 8);云纹裸胸鳝与波纹裸胸鳝的最远(0.531 2)。(3)在7个引物中,有区分云纹裸胸鳝、波纹裸胸鳝及细斑裸胸鳝的特异性片段,可用于这些裸胸鳝的鉴定。

The RAPD （Random Amplified Polymorphic DNA） technique was applied to study the genetic diversity and the genetic relationship of four Gymnothorax species, including four wild populations （ G. flavimarginatus, G. chilospilus, G. undulates and G. fimbriatus） captured from the offshore area of Hainan, China. 29 random primers were used in the, analysis, and the genetic relationship of these Gymnothorax species was analyzed by UPGMA. The results indicated as follows. First of all, the percentages of polymorphic loci of four populations of Gymnothorax, G. flavimarginatus, G. chilospilus, G. undulates and G. fimbriatus were 68.65 %, 57.00 %, 50.80 % and 67.42 %, respectively. The percentages of the heterozygosity of the above four populations of Gymnothorax were 0.222 1%, 0.207 4 %, 0.166 6 % and 0.221 2 %, respectively. It denoted that the level of genetic diversity of them was high and the genetic status was good. Secondly, the interspecies genetic distance and clustering analysis showed that： among four Gymnothorax species, the genetic distance between G. flavimarginatus and G. fimbriatus was minimum （0.340 6）,and that between G.flavimarginatus and G. chilospilus took the second place （0.386 8）, and that between G. chilospilus and G. undulates was maximum （0.531 2）. Finally, among the fragments generated by 8 primers, we found some specific fragments which can be used to identify these Gymnothorax.