中国菜蛾盘绒茧蜂地理种群遗传结构研究
发布时间：2018-12-07 09:49
【摘要】：本论文利用线粒体基因序列和微卫星标记对我国菜蛾盘绒茧蜂地理种群的遗传结构进行了研究,通过分析种群遗传多样性参数、种群遗传结构和群口历史,明确了不同地理种群间的遗传分化程度,探讨了影响种群分化的因素,具体结果如下:(1)扩增得到我国菜蛾盘绒茧蜂12个地理种群共158个个体的2段线粒体基因序列和17个微卫星位点标记,覆盖了我国代表性区域。其中cox1共7个单倍型,cytb共8个单倍型,cox1和cytb联合区域共12个单倍型。17个微卫星位点共检测到242个等位基因,每个种群的等位基因总数均大于50。(2)利用两种分子标记进行分析,分析我国12个菜蛾盘绒茧蜂种群内存在明显的遗传分化。其中基于2个线粒体基因序列的遗传分化系数Fst在 0.074~0.917之间,66组两两种群间共42组存在显著的遗传分化;基于17个微卫星位点的遗传分化系数Fst在 0.006~0.286之间,66组两两种群间共50组存在显著的遗传分化。云南地区种群的核苷酸多样性和单倍型多样性大于其他种群,各种群的多态信息含量均大于0.500。12个种群的等位基因平均数(MNA)、观测杂合度(Ho)、期望杂合度(He)、基因丰富度(Ar)范围分别为:4.765到8.000,0.590到0.783,0.656到0.788,3.067到3.821。(3)基于两种分子标记构建的NJ树,以及2个线粒体基因单倍型网状分析表明,我国菜蛾盘绒茧蜂很可能分化成遗传上不同但与地理位置相关的3个支系:北方支系、中部支系和西南支系。北方支系包括新疆地区及东北地区范围的种群,中部支系包括陕西地区、北京地区、山东地区、湖南地区及两广地区范围的种群,西南支系包括云南地区及四川地区的种群。以云南种群为代表的西南支系明显与其他支系间存在遗传分化,新疆种群和东北种群为代表的北方支系也明显与中部支系间存在遗传分化。单倍型进化树分化时间分析表明,西南支系与其他支系最早于410万年前出现分化,北方支系与中部支系最早于90万年前出现分化。(4)利用两种分子标记方法计算出的种群遗传距离与种群地理距离作的相关性状点状分析(Mantel-test)表明,菜蛾盘绒茧蜂种群间的遗传分化与地理位置存在显著相关性(线粒体基因:r=0.595;P=0.001;微卫星标记:r=0.651;P=0.012)。利用BAPS(线粒体基因序列和微卫星标记)、GENELAND(线粒体基因序列和微卫星标记)和STRUCTURE(微卫星标记)等3种方法进行分析。基于线粒体基因和微卫星标记的BAPS分析均将我国菜蛾盘绒茧蜂分为3个群组。基于线粒体基因的GENELAND分析将我国菜蛾盘绒茧蜂分为4个群组(新疆两个种群被分为两个不同分支),基于微卫星标记则分为3个群组。基于微卫星标记的STRUCTURE分析同样将我国菜蛾盘绒茧蜂分为3个群组。发现两种分子标记的结果因数据类型的不同,产生的结果并不完全一致,但均表明:我国菜蛾盘绒茧蜂存在3个群组,即西南群组、中部群组与北方群组,与进化树结果一致。(5)通过两种分子标记对菜蛾盘绒茧蜂12个种群的基因流进行分析,结果表明3个群组间基因流水平都较低,低水平的基因流是由于菜蛾盘绒茧蜂不具有迁飞性且本身存在地理隔离现象引起。(6)基于线粒体基因序列的中性检验结果表明,黑龙江哈尔滨、陕西杨凌、广西南宁、吉林长春、新疆乌鲁木齐、新疆阿拉尔、云南昆明等7个种群的Tajima’s D值从 2.333~2.611,显著背离0。通过分析3个群组菜蛾盘绒茧蜂的错配分布发现,观测值与模拟值基本符合,说明该群组均符合群体扩张假说(G1:P=0.250;G2:P=0.810;G3:P=0.980;G1=SC,G2=MC,G3=NC)。
[Abstract]:In this paper, the genetic structure of the geographical population of the Chinese cabbage moth is studied by using the sequence of the mitochondrial gene and the microsatellite marker. The genetic diversity parameters, the genetic structure of the population and the history of the population are analyzed, and the degree of genetic differentiation among the different geographical populations is determined. The factors influencing the population differentiation were discussed. The specific results are as follows: (1) The 2-segment mitochondrial gene sequence and 17 microsatellite loci markers of 158 individuals in 12 geographical populations of China's vegetable moth, which is a representative region of China, are covered. Among them, cox1 was 7 single-fold, and the total number of cox1 and ctb was 12 single-fold. The total number of alleles in 17 microsatellite loci was greater than 50. (2) Two kinds of molecular markers were used for the analysis, and there were obvious genetic differentiation in the population of the 12-vegetable moth. 鍏朵腑鍩轰簬2涓嚎绮掍綋鍩哄洜搴忓垪鐨勯仐浼犲垎鍖栫郴鏁癋st鍦，
本文编号：2367008
[Abstract]:In this paper, the genetic structure of the geographical population of the Chinese cabbage moth is studied by using the sequence of the mitochondrial gene and the microsatellite marker. The genetic diversity parameters, the genetic structure of the population and the history of the population are analyzed, and the degree of genetic differentiation among the different geographical populations is determined. The factors influencing the population differentiation were discussed. The specific results are as follows: (1) The 2-segment mitochondrial gene sequence and 17 microsatellite loci markers of 158 individuals in 12 geographical populations of China's vegetable moth, which is a representative region of China, are covered. Among them, cox1 was 7 single-fold, and the total number of cox1 and ctb was 12 single-fold. The total number of alleles in 17 microsatellite loci was greater than 50. (2) Two kinds of molecular markers were used for the analysis, and there were obvious genetic differentiation in the population of the 12-vegetable moth. 鍏朵腑鍩轰簬2涓嚎绮掍綋鍩哄洜搴忓垪鐨勯仐浼犲垎鍖栫郴鏁癋st鍦，
本文编号：2367008
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