基于微卫星标记的美国白蛾中国种群入侵遗传学研究

发布时间：2018-03-30 15:59

  本文选题：美国白蛾　切入点：微卫星标记　出处：《北京林业大学》2016年博士论文

【摘要】：美国白蛾Hyphantria cunea隶属于鳞翅目Lepidoptera灯蛾科Arctiidae,是一种重要的世界性入侵昆虫,对我国农林业生产造成了极大损失。本研究在开发美国白蛾微卫星标记基础上,通过调查分析美国白蛾在我国的传播扩散历史,结合微卫星标记和线粒体基因,研究了我国美国白蛾种群的遗传多样性和种群遗传结构；进而分析了美国白蛾的入侵扩散路径、地理距离、环境差异、山脉阻隔和防治措施等多种因素对遗传分化的影响。主要研究结果如下：1、开发了美国白蛾的微卫星标记通过微卫星富集文库的方法开发了48个微卫星分子标记。将富集文库中得到的序列分成Unique, UnBLASTable, Grouped和Redundant 4 f中类型,分析表明,Grouped序列不适合用于微卫星引物设计。用来自3个种群的美国白蛾对48个微卫星位点的遗传多样性进行检验。每个位点的等位基因个数从2到5个不等,平均为3个。观测杂合度和期望杂合度分别为0～0.958和0～0.773。153个位点-种群组合中有18个组合显著偏离哈迪-温伯格平衡。此外,有一对位点表现出显著的连锁不平衡。在中性检验中,有两个位点成为正向选择的候选位点,而其他位点均为中性选择。另外,还通过克隆微卫星位点的等位基因,研究了这些位点的变异模式,检验了FsT和RST两种种群分化的算法在不同变异模式下的表现,发现FsT更加稳定。本研究开发的微卫星引物,为美国白蛾种群遗传学研究奠定了基础。2、调查和分析了美国白蛾的扩张历史通过文献调研的方法分析了美国白蛾新增疫区的数量、空间分布和范围随时间的变化,重现了美国白蛾在我国的扩散历史和传播路径。美国白蛾在入侵我国的最初25年里扩散速度较慢,1998-2003年有一个比较明显的迟滞阶段,而最近10年扩散速度突然加快。初步分析认为,美国白蛾传播扩散过程可能受到人类活动、防治措旋、地理阻隔和气候等多种因素的影响。研究结果为开展该害虫的入侵生物学研究和相关进化生物学和种群遗传学问题的验证提供了有利条件。3、阐明了中国美国白蛾种群的遗传多样性和群体遗传结构及其影响因素为研究中国的美国白蛾种群入侵扩散历史和遗传变异的关联,以及地理距离、环境差异、防治措施等对遗传结构的影响,本研究选取18个微卫星标记检测了24个中国种群和2个起源地种群共657个标本的基因型,并对其中70个个体的线粒体DNA进行了测序。分别用系统树、贝叶斯聚类(STRUCTURE, GENELAND和TESS)和多元主成分分析的方法分析了种群遗传结构；用近贝叶斯(ABC)的方法检验了不同入侵历史的假设情形；用多重矩阵随机化回归方法评估了地理距离和环境差异对遗传分化的相对贡献。结果表明,中国种群的平均等位基因丰富度和线粒体单倍型多样性远低于美国原产地种群,说明美国白蛾在入侵过程中发生了显著的瓶颈效应；根据核基因标记分析发现,我国的美国白蛾种群有东部和西部两个不同的亚种群,并在二者之间形成接触区；ABC分析表明,美国白蛾入侵我国之后发生了向西的种群扩张；地理距离比环境差异对遗传分化的贡献更大,且地理阻隔更有可能限制了两个亚种群间的基因流。通过将遗传学数据和种群扩张的历史记录相结合,发现地理阻隔和大规模防控可能导致了两个亚种群的形成和维持。
[Abstract]:The American white moth Hyphantria cunea belongs to Lepidoptera Noctuidae Lepidoptera Arctiidae, is a kind of important world invasion insects, on China's agriculture and forestry production caused great losses. In this study, the development of American white Ewei microsatellite markers on the basis of analysis of the history of American white moth spread spread in China through investigation, combined with micro satellite markers and mitochondrial genes, genetic studies of Chinese American white moth population diversity and population genetic structure; and then analyzes the intrusion of hyphantriacunea diffusion path, geographical distance, environmental difference, various factors and preventive measures of mountains on genetic differentiation. The main results are as follows: 1 microsatellite markers the development of American white moth by microsatellite enriched library method developed 48 microsatellite markers. The sequences obtained in the enriched library is divided into Unique, UnBLASTable, Grouped and Redu Ndant analysis of 4 f types, showed that the Grouped sequence is not suitable for microsatellite primer design. Tested by genetic diversity from 3 populations of American white moth on 48 microsatellite loci. The number of alleles per locus ranged from 2 to 5, with an average of 3. Observed heterozygosity and the expected heterozygosity were 0 ~ 0.958 and 0 ~ 0.773.153 loci in 18 populations - combination combination of significant deviations from Hardy Weinberg equilibrium. In addition, there is a pair of loci showed significant linkage disequilibrium. In neutral test, there were two loci candidate sites for positive selection, and other sites are neutral. In addition, the cloning of microsatellite loci alleles, study the variation patterns of these loci, FsT and RST to test the performance of two kinds of population differentiation algorithm in different variation mode, found that FsT is more stable. The research and development of micro satellite Star primer,.2 provides a basis for the research of American white moth population genetics, investigation and analysis of hyphantriacunea expansion history analysis of the number of American white moth new epidemic areas through the methods of literature research, spatial distribution and scope changes with time, reproduce the American white moth in China's history and diffusion path of propagation. The slow diffusion of American white moth in the first 25 years of the invasion of China, there is an obvious lag phase of 1998-2003 years, and the last 10 years the diffusion speed suddenly accelerated. The preliminary analysis shows that the American white moth dispersal process may be affected by human activities, preventivemeasures, various influence factors of geographic and climate etc. the research results have provided favorable conditions to carry out the.3 to verify the pest invasion biology of evolutionary biology and population genetics and related issues, clarify the China of American white moth population genetic diversity The factors of population genetic structure and its influence on China cunea population invasion and genetic variation history association, and geographical distance, environmental difference, effect of control measures on the genetic structure, this study selected 18 microsatellite markers to detect the genotypes of 24 Chinese population and 2 populations of origin 657 specimens, of which 70 individual mitochondrial DNA were sequenced. Phylogenetic trees were used to cluster (STRUCTURE, GENELAND, Bias and TESS) and the method of multivariate analysis of principal component analysis of population genetic structure; near Bias (ABC) method to test the hypothetical situation different invasion history; evaluation the relative contribution of geographical distance and environmental differences on genetic differentiation using multiple regression matrix randomization method. The results show that Chinese population average allelic richness and mitochondrial haplotype diversity is The origin of the population than the United States, that the American white moth happened bottleneck effect in the invasion process; according to the nuclear gene marker analysis found that China's population of American white moth in eastern and western two different subspecies, and formed in the contact zone between the two; ABC analysis showed that after the invasion of American white moth China has undergone population expansion westward; with geographical distance than the environment differences on the genetic differentiation of more and more geographic may limit the two subspecies groups. The gene flow and genetic data of population expansion history combining found geographical barriers and large-scale prevention and control may lead to the formation of two subspecies group and maintain.

【学位授予单位】：北京林业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S763.42
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本文编号：1686599