基于线粒体CO I基因序列的广东鲂遗传多样性分析  

Genetic diversity of Megalobrama terminalis based on mtDNA CO I sequences

作　　者：罗纯 谭细畅 翁士创[1] LUO Chun;TAN Xichang;WENG Shichuang(Hydrological Bureau of the Pearl River Water Conservancy Commission,Ministry of Water Resources,Guangzhou 510611,China)

机构地区：[1]水利部珠江水利委员会水文局,广州510611

出　　处：《海洋渔业》2025年第1期1-9,共9页Marine Fisheries

基　　金：水利部重大科技项目(SKS-2022063);西江流域资源环境与生物多样性综合科学考察(2019FY101900)。

摘　　要：为了解广东鲂(Megalobrama terminalis)遗传多样性和种群结构,提出合理的广东鲂种质资源保护策略,测定并分析了珠江及南方沿海5个地理群体(桂平、梧州、肇庆、阳江、琼海)广东鲂104条线粒体CO I基因序列。在平均长度652 bp的CO I序列中共检测到10个变异位点、11个单倍型,总体呈现高单倍型多样性(Hd=0.508±0.058)和低核苷酸多样性(π=0.00116±0.00017)特点。中性检验结果显示,Tajima’s D(-1.6190,0.01<P<0.05)为显著性负值,单倍型网络图具明显的星状结构,且核酸错配分布图为明显单峰,表明广东鲂在历史上经历过种群扩张。AMOVA分析表明,西江水系3个群体(梧州、桂平和肇庆)间几乎不存在遗传分化(F_(st)=-0.01578~0.00286),可能为单一种群,推测原因可能与广东鲂洄游习性以及连续性生境有关;漠阳江水系与西江水系群体间出现轻度遗传分化(F_(st)=0.05531~0.11932),原因可能与更新世时期云开山脉的形成有关;海南岛与大陆群组存在中度遗传分化(F_(st)=0.23700,P<0.005),原因可能与琼州海峡地理阻隔以及样本数量有限有关。阳江群体Hd=0、π=0,可能与瓶颈效应和人工干预以及采样范围受限有关。梧州、桂平和肇庆群体π较高,可作为广东鲂种质资源保护和开发利用的核心群体。阳江和琼海群体π较低,应建立保护区进行优先保护。In order to contribute to the genetic diversity and population structure of Megalobrama terminalis,and propose a reasonable basis for the protection of natural resources,the mtDNA CO I gene of 104 individuals from five geographical populations(Guiping,Wuzhou,Zhaoqing,Yangjiang,Qionghai)along the Pearl River and coasts of the southern China were analyzed.In the 652 bp fragments of the cytochrome oxidase subunit I(CO I),a total of 11 haplotypes and 10 variable sites were detected,and high haplotype diversity(Hd=0.508±0.058)and low nucleotide diversity(π=0.00116±0.00017)features were revealed.The results of the neutrality test showed that Tajima’s D(-1.6190,0.01<P<0.05)was significantly negative,the haplotype network plot had a clear star structure,and the nucleotide mismatch plot was a clear single peak,suggesting that M.terminalis had experienced a population expansion event in history.AMOVA analysis showed that there was almost no genetic differentiation(F_(st)=-0.01578-0.00286,P<0.05)among the three populations in Xijiang river system(Wuzhou,Guiping,Zhaoqing),which might constitute a single population,and it was speculated that migratory habits and continuity of habitats of M.terminalis were the influencing factors.Mild genetic differentiation(F_(st)=0.05531-0.11932)between populations from Moyangjiang and Xijiang river systems might be related to the formation of the Yunkai Mountains during the Pleistocene era.There was moderate genetic differentiation between Hainan Island group and mainland group(F_(st)=0.23700,P<0.005),which might be affected by the geographic isolation of the Qiongzhou Strait and insufficient sample size.Yangjiang population(Hd=0,π=0)might be related to the bottleneck effects and manual interventions as well as limited sampling range.In terms of nucleotide diversity,Wuzhou,Guiping and Zhaoqing populations were higher and should be considered as the core populations for conservation and utilization,while Yangjiang and Qionghai populations were lower and should be prioritized for conser

关 键 词：广东鲂 CO I基因 遗传多样性 种群历史动态 

分 类 号：S917.4[农业科学—水产科学]