滇榄仁谱系地理学、种系分异及其与红河水系变迁的关系研究
张体操
学位类型博士
导师孙航
2010-01
学位授予单位中国科学院研究生院
学位专业植物学
摘要喜马拉雅的隆升引起了一系列的地质事件,其中包括中国西南部的主要河流(大渡河、雅砻江、金沙江、澜沧江、怒江)被袭夺而从古红河分离的一系列水系重建。我们选择了这一区域同水系分布格局有关的代表类群使君子科榄仁树属滇榄仁(Terminalia franchetii var. franchetii)和错枝榄仁(T. franchetii var. intricata)来开展谱系地理研究,进而探讨河流水系演变对植物分布和种系分异的影响。主要研究结果如下:1. 基于测序的滇榄仁谱系地理学研究:基于大范围的采样,我们收集了滇榄仁两个变种几乎所有分布范围的28个居群258个个体。对叶绿体的trnL-F和 pet两个片段进行测序,共检测到12种单倍型。滇榄仁具有高的单倍型多样性(hT = 0.784),但是居群内的遗传多样性较低(hS = 0.124)。使用SAMOVA软件将所有单倍型分成了5个组。组B和组C都显示出金沙江与红河的南北间断模式,且居群分布与河流袭夺前的古河流走向十分相似。L-psbE根据失配分析(多峰曲线)、中性检验、嵌套分支分析(NCA)以及Mantel test的分析结果,我们认为滇榄仁现存的间断分布的模式主要是由于近期经历过种群的替代隔离。基于叶绿体核苷酸平均替代速率,我们推测出了不同分支间的隔离时间大约在0.82-4.39Mya之间,结果与已有的鱼类分子系统的研究结果基本一致,也与现有的地质学文献关于红河改道的时间一致。因此我们认为红河改道造成的河流重建对滇榄仁的分布格局有重要的影响。2. 基于AFLP的滇榄仁原变种遗传多样性和遗传结构研究:我们选择了滇榄仁原变种的21个居群251个个体进行研究。居群间的遗传分化系数(Gst)为0.249,表明居群间有明显的遗传差异。基于Gst计算出居群间的基因流(Nm)为0.754,说明居群间的基因交流不频繁。通过对AFLP标记进行了NJ tree、PCoA、STRUCTURE和Network等遗传结构分析,结果表明滇榄仁原变种的21个居群可以分为两个大的组。和测序的结果相似,两个组都形成了南北间断的遗传结构,分布模式与河流袭夺前的古河流走向十分相似。并且组I的遗传多样性比组II高。总之,AFLP和单倍型分析均揭示这样一个现象:由于水系的变迁导致了滇榄仁由连续分布居群变为间断分布(金沙江/雅砻江等河流与红河),或者过去间断分布居群变连续分布(金沙江上游/下游与雅砻江)。这种变化为进一步探讨该区域植物区系的起源和分布格局的变迁提供了一个新的思路。3. 滇榄仁与错枝榄仁的系统关系:从形态学、ITS序列的系统学以及叶绿体单倍型的研究均表明,两者之间的遗传差异还没有滇榄仁原变种内部居群的遗传差异大。由于二者间生境及气候条件、分布范围存在明显差异,本研究认为这两个变种在叶片形态及毛被上的差异反映了对环境改变的表型可塑性,而这两个邻域分布的变种的形成也反映了由于占据不同的生态位而发生的遗传分化。因此,错枝榄仁实际上是一个由滇榄仁向北和高海拔扩展产生的年轻的类群,而非传统认为是本属的残遗成分。
资助项目Following the rapid uplift of the Himalaya, the reorganization of the major river drainages was primarily caused by river capture events,e.g. those of the Jinshajiang River (comprising the Upper, Middle and Lower Jinshajiang) and its tributaries (Yalongjiang, Daduhe, Jialingjiang), the Nujiang, the Lancangjiang, and the Honghe. We selected Terminalia franchetii var. franchetii and T. franchetii var. intricata in the Sino-Himalayan region to study the relationship with Honghe diversion events. The distribution of this species is predicted to have retained genetic signatures of past hydrological landscape structures. The major result as flowing:1. Chloroplast phylogeography of T. franchetii based on haplotype analysis,Based on a range-wide sampling comprising 28 populations and 258 individuals, and using chloroplast DNA sequences (trnL-trnF, petL-psbE), we detected 12 haplotypes. Terminalia franchetii was found to harbour high haplotype diversity (hT = 0.784) but low average within-population diversity (hS = 0.124). The analysis of genetic structure using SAMOVA showed that the number of population groups equaled five, and all the haplotypes can be divided into five groups. Group B and C identified exhibited a disjunctive distribution of dominant haplotypes between northern and southern valleys, corresponding to the geography of past rather than modern drainage systems.Mismatch distribution (multimodal curve) and neutral tests provided no evidence of recent demographic population growth. We suggest that the modern disjunctive distribution of T. franchetii, and associated patterns of cpDNA haplotype variation, result from vicariance caused by several historical river separation and capture events. By assuming a common mutation rate of the cpDNA-IGS regions, our inferred timings of these events (0.82-4.39 Mya) broadly agrees with both previous geological and molecular estimated time of drainage rearrangements in this region. So we conclude that there were several historical vicariance events play a major role for the distribution of T. franchetii in this region.2. Genetic diversity and structure of T. franchetii var. franchetii based on AFLP analysis,We determined the genotype of 251 individuals of T. franchetii var. franchetii from 21 populations using amplified fragment length polymorphism (AFLP), for our aim is only investigated the relationship between the modern distribution of T. franchetii and geological changes in drainage patterns. The overall estimate of genetic structure (Gst) was 0.249, indicating that clear genetic differentiation existed among the populations. Estimates of gene flow (Nm = 0.754) between populations based on the Gst value revealed that the number of migrants per generation is not frequently.Using Neighbor-Joining tree, Principal Coordinates Analysis, STRUCTURE and network methods, Analyses of AFLP markers identified two main population groups (I and II) and four subgroups (A – D) of T. franchetii. Genetic diversity was lower in Group I than in Group II. The results show that Groups I and II probably once occupied continuous areas respectively along ancient drainage systems and there were several historical separation and capture events that can account for the distribution of T. franchetii in this region. After all,these are good examples of the way in which historical events can change a species’ distribution from continuous to fragmented (Jinshajiang/ Yalongjiang and Honghe), and a disjunct distribution to a continuous one (Upper/Lower Jinshajiang and Yalongjiang). The results provide new insights into the phylogeographic pattern of plants in southwest China.3. Relationships between T. franchetii var. franchetii and T. franchetii var. intricata ,While T. franchetii var. Franchetii and var. intricata slightly differ in overall size and leaf hairiness, these taxa did not exhibit reciprocal monophyly. As results show, the genetic difference between the two varieties is much smaller than that within var. franchetii (Salween population vs. other populationsof this variety). It is also revealed in a phylogenetic analysis of ITS region of Combretoideae. The habitats of var. franchetii and var. intricata have obviously difference. Thus, the differences between the two varieties in overall size and leaf hairiness might reflect different phenotypic responses to environmental changes and the divergent environmental niche spaces they occupy. Based on the reasoning above, we agree with Flora of China that “T. intricata” represents a variety of T. franchetii rather than a separate species.
语种中文
文献类型学位论文
条目标识符http://ir.kib.ac.cn/handle/151853/16116
专题昆明植物所硕博研究生毕业学位论文
推荐引用方式
GB/T 7714
张体操. 滇榄仁谱系地理学、种系分异及其与红河水系变迁的关系研究[D]. 中国科学院研究生院,2010.
条目包含的文件
文件名称/大小 文献类型 版本类型 开放类型 使用许可
张体操.pdf(6267KB) 限制开放--请求全文
个性服务
推荐该条目
保存到收藏夹
查看访问统计
导出为Endnote文件
谷歌学术
谷歌学术中相似的文章
[张体操]的文章
百度学术
百度学术中相似的文章
[张体操]的文章
必应学术
必应学术中相似的文章
[张体操]的文章
相关权益政策
暂无数据
收藏/分享
所有评论 (0)
暂无评论
 

除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。