长薄鳅(Leptobotia elongata)线粒体DNA控制区遗传多样性研究  

Genetic Diversity of Elongate Loach(Leptobotia elongata) Inferred from Mitochondrial DNA Control Region

作　　者：赵刚[1,2] 周剑[2] 杜军[2] 刘光迅[2] 陈先均[2] 朱健[1] 李建林[1] 

机构地区：[1]农业部水生动物遗传育种和养殖生物学重点开放实验室,江苏无锡214081 [2]四川省农业科学院水产研究所,四川成都611731

出　　处：《西南农业学报》2010年第3期930-937,共8页Southwest China Journal of Agricultural Sciences

基　　金：农业部水生动物遗传育种和养殖生物学重点开放实验室开放基金(BM2007-15)

摘　　要：对采自泸州（长江干流）、南溪（长江干流）、柏溪（金沙江段）、攀枝花（雅砻江段）、重庆（嘉陵江段）4个流域的45尾长薄鳅（Leptobotia elongata）的线粒体DNA控制区部分序列（798 bp）进行了扩增,共检测出19个单倍型,未发现群体间有共享的单倍型,5群体单倍型多样性在0.833~1.000之间,显示不同流域的长薄鳅群体单倍型类型较为丰富。分析了D-Loop的碱基组成、变异情况和核苷酸序列差异,计算了核苷酸多样性（π）、单倍型多样性（h）、FST值和基因流数值（Nm）,构建了长薄鳅不同单倍型分子系统树和中间网络图。5个群体内各序列核苷酸多样性指数（π）在0.276%~0.905%之间;群体间遗传距离范围为0.0028~0.0092,结果显示长薄鳅自然群体存在较丰富的线粒体控制区序列多态性（h=0.916,π=0.00450）,Tajima’s D统计（？2.09890）和Fu’sFs统计（？7.56940）分析都显示各种群之间差异显著（P〈0.05）,但FST值（FST〈0.05）的分析结果显示重庆、柏溪、南溪、攀枝花和泸洲种群间没有明显的遗传分化,暗示了柏溪和攀枝花种群历史上,可能发生过群体扩张和种群瓶颈,而泸州、南溪和重庆种群一直是平衡种群。Nm值计算结果显示各地理种群间无明显基因交流,暗示了长薄鳅虽然在各条不同的河流里洄游产卵,但并未因此而产生独立分化的群体。所有群体中,泸洲和攀枝花种群的遗传多样性比重庆、柏溪和南溪种群丰富。进行长薄鳅人工繁殖时,可以将遗传多样性较丰富地区的个体补充到人工繁殖中来,以提高长薄鳅的遗传素质,为人工增殖放流提供遗传多样性更丰富的个体。In this paper,forty five Leptobotia elongatas were collected from four watershed including Luzhou,Nanxi,Baixi,Panzhihua and Chongqing.Its mt RNA control region sequence（798 bp） was amplified.19 haplotypes were detected without haplotype shared among populations and the diversity of haplotypes were 0.833-1.000,indicating the abundance of haplotypes within different watershed.Base composition of D-Loop,variance and nucleotide diversity were analyzed,meanwhile,haplotype diversity（h）,Fst and gene flow numbers were also calculated.The phylogenetic tree of Leptobotia elongata＇s different haplotype and network picture were constructed.Nucleotide diversity within each sequence of five groups were 0.276 %-0.905 % and the genetic distance between populations were 0.0028-0.0092,indicating there existed sequence polymorphism in natural populations of Leptobotia elongata（h=0.916,π=0.00450）.It showed significant genetic differentiation（P0.05） among populations in results of Tajima＇s D（–2.09890）and Fu＇s Fs（–7.56940）statistic.But there was no significant differentiation and gene flow among populations of Chongqing,Baixi,Nanxi,Panzhihua and Luzhou populations according to the result of FST analysis and Nm calculation,suggesting group distension and bottleneck happened in the history of Baixi and Panzhihua.But the populations of Luzhou,Nanxi and Chongqing were the balance populations all the time.The results showed there were no apparent gene flow,which suggested that there was no independent population though Leptobotia elongatas spawned in different rivers.Genetic diversity of Luzhou and Panzhihua populations were more abundant than that of populations of Chongqing Baixi and Nanxi.So adding the individuals from the region of genetic diversity in artificial propagation was good to enhance genetic predisposition

关 键 词：长薄鳅 线粒体DNA 控制区序列 种群遗传结构 遗传多样性 

分 类 号：S965.116[农业科学—水产养殖]