基于微卫星标记的青岛绿潮浒苔种群的遗传多样性

发布时间：2018-03-20 10:24

本文选题：浒苔　切入点：遗传多样性　出处：《暨南大学》2015年硕士论文　论文类型：学位论文

【摘要】：2007年~2013年,我国青岛海域连续七年暴发大规模绿潮。特别是在2008年的夏天,青岛暴发了世界上最大规模的绿潮,引起了严重的社会问题和海洋生态问题。绿潮的物种组成、种群遗传结构和遗传多样性的研究对查明绿潮暴发的原因,寻找合适的预防措施具有重要意义。为掌握青岛绿潮的物种组成,了解绿潮种群的遗传结构和遗传多样性,本文于2013年6月19日在青岛绿潮现场的21个站点收集了210个漂浮绿藻样品,利用nr DNA ITS、rbc L和5S基因序列对采集到的样品进行了分子鉴定,进一步利用自行开发的微卫星(simple sequence repeat,SSR)引物,对浒苔(Ulva prolifera)的种群遗传结构和遗传多样性进行了分析。nr DNA ITS和rbc L序列分析结果显示,210个绿藻样品全部为Ulva linza-procera-prolifera(LPP)复合体。5S序列的分析进一步证实,这些绿潮样品均为浒苔,表明青岛绿潮,至少2013年的绿潮,是由单一物种浒苔形成的。基于浒苔EST序列和ISSR引物,开发出8对浒苔微卫星引物。SSR标记共检测到17个等位基因。SSR位点的观察等位基因数为1~3个,平均观察等位基因数为2.125个,有效等位基因为1.000~1.235,平均有效等位基因是1.160。Nei‘s基因多样性(H)为0.000~0.189,平均值为0.064;香农指数(I)为0.00~0.367,平均为0.133,这些结果提示青岛绿潮浒苔种群的遗传多样性较低。考虑到浒苔可行有性生殖、无性生殖和单性生殖等三种生殖方式,其中以无性生殖为最主要的方式,我们推测浒苔的生殖方式和对环境的高度适应性,可能是其形成单一物种绿潮的原因;其较低的遗传多样性除了与生殖方式有关外,还可能与本文所用的微卫星标记引物的来源有关。研究结果可为阐明青岛绿潮的形成与暴发机制、明确绿潮的来源提供参考和依据。
[Abstract]:From 2007 to 2013, there were seven consecutive years of large-scale green tides in Qingdao, China. Especially in the summer of 2008, Qingdao experienced the largest green tide in the world, causing serious social and marine ecological problems, and the species composition of the green tide. The study of population genetic structure and genetic diversity is of great significance in identifying the cause of green tide outbreak and finding appropriate preventive measures. In order to understand the species composition of green tide in Qingdao and to understand the genetic structure and genetic diversity of green tide population, In June 19th 2013, 210 samples of floating chlorophyta were collected from 21 sites of the Green Tide site in Qingdao. The samples were identified by using nr DNA ITSc L and 5S gene sequences. Further more, using self-developed primers for simple sequence repeats, The population genetic structure and genetic diversity of Ulva prolifera were analyzed. The results showed that all 210 samples of Chlorophyta were Ulva Linza-procera-prolifera LPP complex. The results showed that the green tide of Qingdao, at least 2013, was formed by a single species, Enteromorpha enteromorpha, based on EST sequence and ISSR primer. A total of 17 alleles. SSR loci were detected by 8 pairs of microsatellite primers. The number of observed alleles was 1 ~ 3, and the average number of observed alleles was 2. 125. The effective allele was 1.0000.235, the average effective allele was 1.160.Neis gene diversity (H) was 0.0000.1899 (mean 0.064), and the Shannon index (I) was 0.000.367with an average of 0.133.These results indicated that the genetic diversity of green tide Enteromorpha enteromorpha population in Qingdao was low, considering the possibility of sexual reproduction of Enteromorpha enteromorpha. Asexual reproduction and parthenogenesis, among which asexual reproduction is the most important way, we speculate that the reproductive mode of Enteromorpha margin and its high adaptability to the environment may be the cause of the green tide of a single species. The low genetic diversity may also be related to the origin of microsatellite marker primer used in this study. The results can be used to elucidate the mechanism of green tide formation and outbreak in Qingdao. Make clear the source of green tide to provide reference and basis.
【学位授予单位】：暨南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X55;Q943

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