海南岛4条河流李氏吻虾虎鱼的群体遗传结构分析

Analysis of population genetic structure of Rhinogobius leavelli(Herre,1935)in four rivers of Hainan Island

海南岛众多独立入海的河流形成天然的生物地理屏障,造就了海南丰富的淡水鱼类资源。李氏吻虾虎鱼〔Rhinogobius leavelli(Herre,1935)〕因利用价值低而未被人工大量养殖驯化,可作为评估鱼类遗传多样性的理想物种。本文基于COX1和D⁃loop分子标记,分析了海南岛南渡江、珠碧江、三亚河和陵水河等4条河流中李氏吻虾虎鱼的种群遗传结构。遗传多样性分析显示,4条水系中43尾李氏吻虾虎鱼COX1、D⁃loop及联合基因中分别检测出8、14、22个变异位点和6、7、8个单倍型,平均单倍型多样性和核苷酸多样性分别是0.617、0.647、0.649和0.0039、0.0094、0.0063,其中三亚河与陵水河种群的遗传多样性均较高。系统发育树结果均显示,李氏吻虾虎鱼4个水系的5个地理种群聚类为2个进化分支,其中三亚河与陵水河种群聚为一支,南渡江、珠碧江种群聚为一支。遗传距离分子方差分析显示,李氏吻虾虎鱼群体的遗传变异主要来自种群间。上述结果表明,海南岛李氏吻虾虎鱼表现出显著的遗传分化,遗传多样性水平较高,可能因不同水系的隔离效应和李氏吻虾虎鱼较弱的迁移能力导致其种群间的遗传分化,本文为海南岛河流生态系统中鱼类种质资源多样性的研究提供遗传学参考。

Numerous independent rivers form a natural biogeographical barrier,creating rich freshwater fish resourc⁃es in Hainan Island.R.leavelli has not been domesticated in large numbers because of its low utilization value,so it can be used as an ideal species to evaluate the genetic diversity of fish.Based on COX1 and D⁃loop molecular markers,the population genetic structure of R.leavelli in Nandujiang,Zhubijiang,Sanyahe and Linshuihe rivers was analyzed.Genet⁃ic diversity analysis showed that 8,14,22 variation sites and 6,7,8 haplotypes were detected respectively in COX1,D⁃loop and combined genes of the 43 R.leavelli in four rivers,and the average haplotype diversity and nucleotide diversity were 0.617,0.647,0.649 and 0.0039,0.0094,0.0063,respectively.The genetic diversity of Sanyahe and Lingshui⁃he populations was higher than other pupulations.Phylogenetic tree analysis indicated that the 5 populations of 4 rivers clustered into 2 evolutionary branches,among which the populations of Sanyahe and Lingshuihe rivers clustered together and the populations of Nandujiang and Zhubijiang rivers clustered together.Analysis of molecular variance showed that the genetic variations of R.leavelli in 4 rivers mainly occured between populations.The above results indicate that the ge⁃netic differentiation of R.leavelli in Hainan Island is significant and the level of genetic diversity is high,which may be caused by the isolation effect of different water systems and the weak migration ability of R.leavelli.This paper provides a genetic reference for the study of fish genetic diversity in the river ecosystem of Hainan Island.