秦岭地区黑翅雏蝗的谱系地理学

【作者】 张丽丽；

【导师】 许升全；

【作者基本信息】 陕西师范大学 ， 动物学， 2009， 硕士

【摘要】 黑翅雏蝗(Chorthippus aethalinus(Zubovsky))是一种北方广布种,在国内分布于东北,内蒙以及黄土高原,在秦岭均有分布;在国外分布于俄罗斯的西伯利亚等地区。秦岭横贯中国中部,是我国地理上的南北分界线、黄河和长江的分水岭。在动物地理区划上,该区域是古北界和东洋界的分界区。因此生活在南北两侧不同区域的同种生物的不同种群间在分子上可能存在一定的差异,利用DNA序列分析方法探讨秦岭南北地区黑翅雏蝗种群的遗传分化,即秦岭山对物种的扩散是否有阻隔作用,目前还鲜有研究。本研究通过对秦岭地区黑翅雏蝗6个地理种群的核基因ITS、线粒体D-loop区序列进行了序列分析,首先用ContigExpress软件对所得的序列进行拼接校对,然后采用ClustalX1.83软件对序列进行比对、剪裁,将剪裁后的序列导入MEGA4.0中计算遗传距离、DnaSP4.0和Arlequin3.11中进行单倍型分析和序列组成分析,并使用距离法和网络分析法对核基因ITS和线粒体D-loop区定义的单倍型序列数据构建单倍型系统发育树;同时,在SPSS16.0中对6个地理种群的13个形态特征测量数据进行Z值标准化处理,然后用Between-group linkage法聚类分析。通过分析分子数据和形态学数据,得到以下结论:1.线粒体D-loop区和核基因ITS进化均较快,且D-loop区快于ITS基因,二者均可以用于黑翅雏蝗各地理种群间的研究,但由于这两个基因均为非编码区,在序列分析中很难确定碱基的缺失和插入,故本文在分析中未考虑碱基的缺失和插入,如果本试验能结合一个进化快且又是编码区基因,其分析结果可能更有可信度。2.从线粒体D-loop区和核基因ITS构建的单倍型系统发育树来看,两个基因均支持秦岭地区黑翅雏蝗可被划分为两大类群,即秦岭南坡类群和秦岭北坡类群这一观点;线粒体D-loop区能更好地将单倍型按地理种群聚在一起,而ITS基因揭示南坡各种群有交错分布的现象:单倍型网络图显示佛坪(F)种群与其他种群相比似乎是较古老的种群。3.形态学数据并没有很好地支持分子数据揭示的秦岭对黑翅雏蝗各地理种群的阻隔作用,形态数据更多的反映出温度、湿度、光照、海拔等外界因素对黑翅雏蝗形态的影响。4.通过对秦岭地区6个黑翅雏蝗地理种群间遗传分化的探讨,其结果从一定程度上反映了秦岭山系对这6个地理种群遗传分化有地理阻隔作用,高大的秦岭山阻碍了种群的扩散和基因交流,各地理种群的遗传分化程度高,特别是南北种群间的遗传分化较高。5.通过单倍型分析和对种群遗传结构进行分析,推测秦岭地区黑翅雏蝗现在的分布格局可能是地理隔离造成的栖息地破碎化和近代种群的迁移形成的。更多还原

【Abstract】 Chorthippus aethalinus (Zubovsky) is a widespread grasshopper in north, In china which distributes in Northeast, Inner Mongolia and the Loess Highlands, as well as in Qinling. In overseas which distributes in the Siberia areas of Russia.Qinling Mountains which traverses in the central of china, is the boundary of the north and the south on the geographical location, the watershed of the Yellow River and the Changjiang River water system, intersectant converge and transitional area between the palaearctic region and oriental region. Therefore populations may have divergence on molecular which distribute in the north and south of the Qinling area, we use DNA sequencing to discuss those populations’s genetic differentiation, meanwhile whether species diffusing is obstructed by Qinling Mountains. It is worth to discuss for usThis study did the sequencing of mtDNA D-loop region and rDNA ITS gene of 6 z.aethalinus populations in the Qinling Mountains. First we used Contig Express software to splice and correct obtained sequences, and used ClustalX1.83 to clip, then calculate genetic distance in MEGA4.0 and did haplotype analysis and sequencing in Dnasp4.0 and Arlequin 3.11, finally haplotypes defined by 2 genes were used to construct phylogenetic tree by distance-based method and network analysis method. Meanwhile, after standardizing the 13 characteristic data from these 6 population in the Qinling Mountains by SPSS 16.0, then clustered data by Between-group linkage method.By analyzing the DNA sequence data and morphological data, gave the following conclusions: 1. mtDNA D-loop region and rDNA ITS gene evolved more quickly, and mtDNA D-loop was faster than ITS gene. 2 genes could be used to research population genetic divergence, but they were non-coding regions, so bases’ deletion and insertion were difficult to determine, if adopting 1 gene that evolved much faster and code, the conclusion might be more convincible. 2. By phylogenetic tree, haplotypes defined by 2 genes were divided into 2 clades: the south group of Qinling, the north group of Qinling, ITS gene revealed that populations staggered each other in the south of Qinling Mountains. Haplotypes network analysis revealed F population that might be older population than others. 3. Morphological data was not support the result of molecular data, molecular data was more sensitived to geographical isolation, but morphology was affected by environment. 4. According to genetic differentiation analysis among 6 populations, which suggested that geographical isolation shaped by Qinling Mountains, strapping Qinling Mountains limited gene flowing and diffusion among populations, populations had high genetic differentiation, especially more higher genetic differentiation between the north group of Qinling Mountains and the south group of Qinling Mountains. 5. According to haplotypes analysis and population genetic structure analysis, we speculated that z. aethalinus present distribution may be shaped by habitat fragmentation and modern populations colonization.更多还原