【作者】 陈省平；

【导师】 包振民； 何建国；

【作者基本信息】 中国海洋大学 ， 海洋生物学， 2007， 博士

【摘要】 赤点石斑鱼是我国重要的经济鱼类和养殖的重要种类,由于过度捕捞和生境变化,资源量严重衰竭,加之其独特的生殖习性,其种质资源现状及其可持续利用前景令人堪忧。本研究以我国东海、南海的赤点石斑鱼野生群体为研究对象,采用多种分子标记技术对其群体遗传多样性和遗传结构进行了研究,以阐述其种质资源现状,为赤点石斑鱼遗传育种和渔业管理提供理论依据。本研究共采集了我国东海和南海的赤点石斑鱼7个地理群体共88个个体,采用了线粒体DNA控制区、AFLP和微卫星三种分子标记研究赤点石斑鱼的群体遗传结构和群体遗传多样性。1.对赤点石斑鱼控制区部分序列进行分析。赤点石斑鱼群体的单倍型多态很高,采用中性检验和核苷酸不配对分布分析了赤点石斑鱼的群体历史动态,分子方差分析和Fst的结果显示赤点石斑鱼在分布区内存在显著的种群遗传结构。2.利用13对选择性引物对赤点石斑鱼群体遗传变异进行了AFLP分析,13对引物在7个群体中扩增出941个条带,7个群体的多态位点比例为18.40%～47.70%,Nei遗传多样性指数为0.0447～0.1429,Shannon多样性指数为0.0665～0.2141;分子方差分析和Fst的结果群体间遗传差异显著;检测到多条种群间特异性条带,可以作为种群鉴别的标志。3.利用赤点石斑鱼的近缘种微卫星序列筛选建立了适合赤点石斑鱼的微卫星体系,研究了赤点石斑鱼群体在7个微卫星位点上的变异情况,在7个基因位点上共检测到45个等位基因,每个引物扩增出4～11个等位基因,平均每个引物获得6.4个等位基因,7个群体的观测杂合度(Ho)在0.2190～0.5079之间,预期杂合度(He)在0.3683～0.6689之间;7个群体间的遗传距离在0.0665～0.7093之间,两两群体间的Fst值在0.0048～0.2558之间,大部分群体间遗传差异显著。线粒体DAN控制区、AFLP和微卫星结果表明赤点石斑鱼不同地理群体间存在不同程度分化,可划分为两个独立地理种群,三亚和湛江群体为一地理种群,其余群体为一个地理种群;与其他鱼类的多样性指数的比较分析显示赤点石斑鱼遗传多样性水平较低。更多还原

【Abstract】 The red spotted grouper Epinephelus akaara is of commercial importance and an attractive target fish for aquaculture. Presently, the red spotted grouper resources have been depleted to be in severe danger partly due to overfishing and its special particularities of reproduction. Population genetics of the red spotted grouper collected from East China Sea and South China Sea were studied by different DNA marker technologies. The results of this study will lay a theoretic foundation not only for the protection of the rare resources but also for the genetic breeding studies.In this study, in order to estimate the genetic structure and genetic diversity of E. akaara, 88 individuals sampled from 7 locations throughout the distribution range of E. akaara in China were analyzed by mtDNA, AFLP and SSR.1. Mitochondrial DNA variation was analyzed using sequence data from control region. Nucleotide diversity was high in E. akaara; The demographic history of E. akaara was examined using neutrality tests and mismatch distribution analyses, Molecular variance analyses and pairwise Fst revealed significant genetic structure among seven populations.2. 13 AFLP primers were used to investigate the genetic variation in E. akaara. A total of 941 loc were detected from 7 populations; the proportion of polymorphic loci, the Nei genetic diversity and Shannon genetic diversity index of 7 populations were 18.40%～47.70%, 0.0447～0.1429, 0.0665～0.2141, respectively. Molecular variance analyses and pairwise Fst showed significant genetic differentiation among seven populations. Some population specific bands were detected, these specific markers could be used for population identification.3. The genetic variations of 7 populations of E. akaara were assessed at 7 SSR loci. A total of 45 alleles were detected in the loci investigated, and the number of alleles at each polymorphic locus was in the range from 2 to 11, with an average value of 6.4. The Ho and He values of 7 populations were 0.2190～0.5079, 0.3683～0.6689, respectively. The genetic distance and pairwise Fst among populations varied from 0.0665 to 0.7093, 0.0048～0.2558, respectively. The pairwise Fst values showed most pairwises were statistically significant.Based on mtDNA, AFLP and SSR results, significant genetic differentiations among all populations were revealed, and 7 populations could be divided into two geographic populations. E. akaara compared to those in other teleosts assayed with the same techniques showed low genetic diversity.更多还原