基于线粒体Cytb序列的广东地区大刺鳅群体遗传多样性分析  

Population Genetic Diversity of Mastacembelus armatus in Guangdong Basedon the Mitochondrial Cytb Sequence

作　　者：詹华伟 叶树政 陈锭娴 王凯丰 刘兰苑 龚剑[2] 韩崇 李强[1] ZHAN Hua-wei;YE Shu-zheng;CHEN Ding-xian;WANG Kai-feng;LIU Lan-yuan;GONG Jian;HAN Chong;LI Qiang(School of Life Sciences,Guangzhou University,Guangzhou 510006,PRC;School of Environmental Science and Engineering,Guangzhou University,Guangzhou 510006,PRC)

机构地区：[1]广州大学生命科学学院,广东广州510006 [2]广州大学环境科学与工程学院,广东广州510006

出　　处：《湖南农业科学》2024年第3期1-6,共6页Hunan Agricultural Sciences

基　　金：国家自然科学基金(41673110);广州大学2023年大学生创新创业训练项目(S202311078102)。

摘　　要：为了解广东地区大刺鳅遗传多样性特征,采集广东地区6个水系(西江、北江、东江、鉴江、漠阳江、韩江)193尾大刺鳅样本,测定其线粒体Cytb序列,并利用MEGA 6.0软件碱基组特点和遗传距离、DNAsp 5.0软件分析各群体的多样性水平和Network 5软件绘制单倍型网络关系图。结果表明:大刺鳅Cytb序列长度1138 bp,在193尾大刺鳅的Cytb序列中,A、C、T、G占比分别为25.9%、32.7%、27.7%和13.6%,遗传距离为0.0002~0.0131,遗传分化指数为0.035~0.866。6个大刺鳅群体共存在38个核苷酸变异位点,定义了20个单倍型,单倍型多样性为0.782,核苷酸多样性约为0.0072。基于线粒体Cytb序列构建的NJ树显示,广东地区的大刺鳅种群分为Ⅰ和Ⅱ两支。其中,支系Ⅰ包含了西江、北江、鉴江和漠阳江群体的部分样本以及东江和韩江群体的全部样本;支系Ⅱ包含了西江、北江、鉴江和漠阳江群体的部分样本。单倍型网络分析显示,西江水系的群体与东江、韩江以及漠阳江群体的亲缘关系较近,而北江群体与东江、西江群体间遗传分化较大。AMOVA分析表明,77.09%的变异来自于组群内群体间,37.92%的变异来自于群体内。核苷酸错配分析及中性检验结果显示,广东大刺鳅整体及各个群体在历史上均没有发生过明显的扩张。广东各水系的大刺鳅群体遗传多样性水平较低,野生种群的遗传多样性总体呈现下降趋势。To understand the genetic diversity of Mastacembelus armatus in Guangdong,we sequenced the mitochondrial Cytb genes of 193 individuals of M.armatus from six rivers(Xijiang River,Beijiang River,Dongjiang River,Jianjiang River,Moyang River,and Hanjiang River)in Guangdong.The base composition and genetic distance were analyzed by MEGA 6.0.The diversity of each population was analyzed by DNAsp 5.0 and the haplotype network was established in Network 5.The results showed that the Cytb sequence of M.armatus was 1138 bp in length.The Cytb sequences of 193 individuals showed the A,C,T and G content of 25.9%,32.7%,27.7%,and 13.6%,respectively.The genetic distance was 0.0002-0.0131,and the genetic differentiation coefficient was 0.035-0.866.A total of 38 nucleotide variation sites and 20 haplotypes were identified in the six populations of M.armatus,with the nucleotide diversity of 0.0072 and the haplotype diversity of 0.782.The neighbor-joining tree established based on mitochondrial Cytb sequence showed that the populations of M.armatus in Guangdong were clustered into two clades:I and II.Clade I contained some individuals from Xijiang River,Beijiang River,Jianjiang River,and Moyang River and all the individuals from Dongjiang River and Hanjiang River.Clade II contained some individuals from Xijiang River,Beijiang River,Jianjiang River,and Moyang River.The haplotype network showed that the population in Xijiang River was closely related to those in Dongjiang River,Hanjiang River,and Moyang River,while the population in Beijiang River was distant from those in Dongjiang River and Xijiang River.The AMOVA results showed that 77.09%and 37.92%of the variations occurred between and within populations,respectively.The results of nucleotide mismatch analysis and neutrality test showed that there was no significant expansion of M.armatus populations in Guangdong.The M.armatus populations in Guangdong demonstrated low genetic diversity.Moreover,the genetic diversity of wild populations showed a decreasing trend.

关 键 词：大刺鳅 遗传多样性 线粒体Cytb序列 亲缘地理 

分 类 号：S937[农业科学—渔业资源] S966.4[农业科学—水产科学]