| 摘要: |
| 为研究洪泽湖河蚬种群遗传多样性及其遗传结构, 采用线粒体细胞色素氧化酶Ⅰ基因(COI) 作为分子标记, 采用PCR 扩增洪泽湖4 个河蚬群体(顾勒河GLH、临淮LH、蒋坝JB 和高良涧GLJ) 的COI 基因片段并进行了序列测定和分析。结果表明, 614bp 长度的核苷酸片段中, 碱基A+T 的平 均含量为65.0%, 明显高于G+C 的含量(35.0%).共检测到73 个多态位点, 多态位点比例为11.9%, 77 个个体中共获22 个单倍型(GenBank 登录号: KM659000-KM659021), 其中包括3 个共享单倍型, 4 个群体的平均单倍型多样性指数h 为0.889, 平均核苷酸多样性指数π 为0.04499, 平均核苷酸差异 数K 为27.622, 其中蒋坝群体的遗传多样性最高, 顾勒河群体的遗传多样性最低。22 个单倍型间的 Kimura 2-paramter 遗传距离为0.002-0.100, 平均遗传距离为0.0514.NJ 法构建的分子系统树显示 22 个单倍型聚为2 个分支。4 个群体间的遗传距离达0.03729-0.04969, 基于群体间遗传距离构建的 NJ 系统树中, 高良涧群体和顾勒河群体聚为一支, 蒋坝群体和临淮群体聚集为一支。AMOVA 分析 表明, 洪泽湖河蚬四群体间总遗传分化系数Fst 为0.06325(P>0.05), 93.67%遗传变异存在于群体内部, 6.33%变异存在于群体间。中性检验结果和歧点分布图显示, 洪泽湖河蚬种群大小保持稳定, 未经历 明显的种群扩张。 |
| 关键词: 遗传多样性 COI 基因 河蚬 洪泽湖 |
| DOI：10.11693/hyhz20141200353 |
| 分类号: |
| 基金项目:江苏省333 工程科研项目, BRA2014319 号; 江苏省三新工程项目, Y2015-18 号; 江苏省青年科学基金项目, BK2012488 号。 |
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| ANALYSIS OF GENETIC DIVERISTY AND POPULATION STRUCTURE OF CORBICULA FLUMINEA IN HONGZE LAKE IN MITOCHONDRIAL COI GENE SEQUENCE |
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LI Da-Ming, ZHANG Tong-Qing, TANG Sheng-Kai, ZHONG Li-Qiang, LIU Xiao-Wei
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Freshwater Fisheries Research Institute of Jiangsu Province, Key Laboratory of Fisheries Resources in Inland Water, Nanjing 210017, China
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| Abstract: |
| To understand the genetic diversity and genetic structure of Corbicula fluminea populations in Hongze Lake, East China, we amplified the mitochondrial cytochromec oxidase subunit I (COI) gene fragments of the populations in four lake areas [Gulehe (GLH), Linhuai (LH), Jiangba (JB), and Gaoliangjian (GLJ)] with PCR (polymerase chain reaction). The PCR products were purified and sequenced, from which 614bp nucleotide sequences were obtained. The results show that: (1) the average contents of A+T(65.0%) were significantly higher than those of G+C(35.0%) in the fragment. Seventy-three polymorphic sites were detected, which represented for 11.9% of the total length of the sequenced COI gene. Twenty-two haplotypes (GenBank accession numbers: KM659000-KM659021) were defined out of 77 individuals from these four populations. The haplotype diversity (h), the nucleotide diversity (π) and the average number of nucleotide differences (K) was 0.883, 0.00799, and 27.622, respectively. The genetic diversity of the JB population was the highest among the four, and the GLH population was the lowest; (2) the Kimura 2-parameters genetic distance among all haplotypes ranged from 0.002 to 0.1, and the average genetic distance was 0.0514. As shown in the NJ phylogenetic tree, 22 COI haplotypes could be divided into two lineages; (3) the genetic distance among the four C. fluminea populations varied from 0.03729 to 0.049. In among-population genetic distance, two populations of GLJ and GLH were clustered in one clade and the other two formed another; (4) analysis of molecular variance (AMOVA) across population showed that the fixation index (Fst) was 0.06325(P>0.05), of which the majority of them (93.67%) was within population, and the rest was among population (6.33%); (5) mismatch distribution and neutrality test indicates that C. fluminea population expansion has not taken place in Hongze Lake. |
| Key words: genetic diversity COI gene Corbicula fluminea Hongze Lake |
