【作者】 陈省平；

【导师】 包振民；

【作者基本信息】 中国海洋大学 ， 海洋生物学， 2004， 硕士

【摘要】 本研究筛选了我国四种主要养殖扇贝：栉孔扇贝、华贵栉孔扇贝、虾夷扇贝和海湾扇贝的特异性AFLP标记，并应用分子标记对栉孔扇贝、华贵栉孔扇贝及其杂交后代进行了遗传结构分析。 栉孔扇贝、华贵栉孔扇贝、虾夷扇贝和海湾扇贝隶属于扇贝科的三个属，四种扇贝间生物学特征和遗传基础方面存在着一定的差异。根据研究结果，在扩增出的510个位点中，四种扇贝只有105个位点上具有相同的扩增带。栉孔扇贝与华贵栉孔扇贝是同属于栉孔扇贝属的两种扇贝，从分类学上讲二者之间的遗传关系在四种扇贝中应该最近，用UPGMA方法构建的四种扇贝的系统树也证明了这一点。实验结果也表明栉孔扇贝和虾夷扇贝共有的扩增位点数也是最高的。栉孔扇贝、虾夷扇贝和海湾扇贝各具有自己的种特异性AFLP标记，可用于三个种的鉴定。虽然没有找到华贵栉孔扇贝特有的AFLP标记，但可以将其它三种扇贝的特异性标记与华贵栉孔扇贝和海湾扇贝共享的3个AFLP标记相结合，就可以将四种扇贝区分开。 在对栉孔扇贝、华贵栉孔扇贝及其杂交后代进行了遗传结构的分析研究中，栉孔扇贝和华贵栉孔扇贝的大部分显性位点都在杂交子代中得到扩增，特别是华贵栉孔扇贝的17个特异性AFLP标记，有13个在子代中得到遗传。说明杂交子代即具有来自于父本的遗传特征，也有来自于母本的遗传特征。从实验结果推断，栉孔扇贝与华贵栉孔扇贝的杂交子代在遗传结构上明显偏向于栉孔扇贝亲本(母本)一方，其机理尚待于进一步研究。 实验中发现，扩增得到的AFLP条带中，除大部分在亲、子代间存在明显遗传关系的扩增带外，还出现少量非遗传关系的扩增带，包括8条只在亲本群体出现而子代群体没有的扩增带和10条只在子代群体出现而亲本群体没有的扩增带。出现亲本群体有而子代群体没有的扩增带，其原因可能是由于亲本双方的同源染色体相互作用造成的，由于双亲的同源染色体相互作用，使酶切位点被修饰或被隐弊，从而不能被扩增。 杂交双亲群体与杂交子代群体有可能在表型性状方面较为相似，在其群体区分和种质鉴定方面，找到特异性标记对其进行鉴定和区分就显得尤为重要。本实验利用E32M54、E35M61、E44M61三个引物组合得到的栉孔扇贝、华贵栉孔扇贝及其交子代的AFLP扩增带谱中，只有E44M61一22位点上的扩增带为华贵栉孔扇贝的特异性AFLP标记，没有找到其它两个群体各自的特异性AFLP标记，但也可以将E44M61一22位点与E32M54一In位点结合起来，即可以区分杂交双亲群体及杂交子代。 本文对四种主要养殖扇贝的遗传多样性进行了研究;同时，为深入探讨栉孔扇贝和华贵栉孔扇贝杂交子代遗传机制，利用AFLP技术从分子水平对栉孔扇贝、华贵栉孔扇贝及其杂交子代的遗传结构进行分析，探讨杂交子代与亲本遗传关系以及遗传结构上的差异、遗传带谱的分布及变化趋势，找出亲本及子代群体的特异性AFLP标记，以期为扇贝的杂交育种工作提供参考。更多还原

【Abstract】 The AFLP technique is used to screen the specific markers of the four main scallop species bred in China and to analyse the genetic structure of Zhikong scallop (Chlamys farreri), Huaguizhikong scallop (Chlamys nobilis) and their Fl reciprocal hybrids.Zhikong scallop, Huaguizhikong scallop, Japanese scallop (Patinopecten yessoensis), Bay scallop (Argopecten irradians) belong to the three genus of Pectinidae. There are some difference in the biological character and genetic base among the four scallop species. According to the result, only 105 of total 510 loci are consistent in the four species. Zhikong scallop and Huaguizhikong scallop belong to the same genus, so the genetic relation of them should be the most close, which is proved through the systematic tree constructed by the UPGMA method. The specific markers of Zhikong scallop, Japanese scallop and Bay scallop can be used for the species identification. As to Huaguizhikong scallop, it can be identified by the combination of the above specific markers and the 3 markers shared by Bay scallop.In this study, most of the dominant loci from Zhikong scallop and Huaguizhikong scallop can be amplified in their hybrid offspring, especially the 13 of 17 specific markers in Huaguizhikong scallop is hereditable. According to the results, the hybrid offspring inherit genetic material from not only the male parent but also the female parent, and the genetic structure of the offspring is significantly partial to Zhikong scallop (the female parent), the mechanism is now in research.It is found that most of the amplified AFLP markers are coincident with the genetic relation, but a few of them are not, including the 8 makers only existing in parents’ population and the 10 only existing in offspring population. The amplified AFLP markers only existing in parents’ population are probably caused by thereciprocity of the parental homologous chromosome, which makes the loci that can be identified by the restriction enzymes be modified or hidden and can not be amplified.It is important to obtain the specific markers for the identification of parent and offspring population which is similar in morphological character. In the AFLP markers from E32M54, E35M61 and E44M61, only E44M61-22 is specific in Huaguizhikong scallop, which can be combined with E32M54-111 to identify the three populations.In order to deeply study the genetic mechanism of hybrid offspring, AFLP is used to analyze the genetic structure of the three populations, to study the difference in genetic structure, the distributing and trend of genetic markers, to find the specific markers of the three populations. Hope that it could provide reference for the scallop hybrid breeding.更多还原