多DNA片段探讨温带竹子的系统发育和网状进化-以箬竹属、铁竹属和赤竹属为主
文献类型：学位论文
| 作者 | 曾春霞 |
| 学位类别 | 博士 |
| 答辩日期 | 2009-01-16 |
| 授予单位 | 中国科学院昆明植物研究所 |
| 授予地点 | 昆明植物研究所 |
| 导师 | 李德铢 |
| 关键词 | 温带竹子支系 竹亚科 系统发育 叶绿体非编码区 ITS GBSSI 网状进化 |
| 其他题名 | large multi-locus phylogeny and reticular evolution of the temperate bamboos (Poaceae: Bambusoideae): with an emphasis on Indocalamus,Ferrocalamus and Sasa |
| 学位专业 | 植物学 |
| 中文摘要 | 1. 八个叶绿体非编码区片段的结果与分析 对温带竹子支系18属68个种（含1变种），基于八个非编码区片段rps16-trnQ, trnT-trnL, rpoB-trnC, trnS-trnG, psaA-ORF170, trnD-trnT, atpH-atpI和rpl32-trnL的联合数据进行了最大简约法和贝叶斯分析，结果表明，虽然温带竹子支系作为单系继续得到强烈支持，但是由于叶绿体非编码区在温带竹子支系非常保守，分辨率较低，多位点、大片段的叶绿体基因组数据仍然不能解决温带竹子支系的深度系统重建问题。筱竹属复合群，青篱竹亚族和倭竹亚族均不是单系；箬竹属、赤竹属、短枝竹属为多系，铁竹属为单系，巴山木竹属、苦竹属、玉山竹属、箭竹属等11个属可能为并系或者多系。研究表明，取样范围和密度对于温带竹子支系的系统重建非常重要，高密度的取样显示以前可能得到支持的类群不是单系，不能轻易用某一个种或少数种来代表一个亚族、属或者组。 2. 核核糖体rDNA ITS结果与分析 对温带竹子支系的16属61个种的116个ITS序列进行了贝叶斯分析，结果发现ITS在温带竹子支系部分属种中来源于同一物种的克隆序列间存在较大的差异，表明ITS在这些物种中为不完全的一致性进化；不同属或者同属的不同种其进化模式和进化速率也不尽相同；根据GC含量、长度变异、碱基替代率和长枝吸引现象等方面证明Sasa shimidzuana_1为一个假基因；温带竹子支系为快速辐射分化的类群，物种间存在复杂的网状进化关系。由于ITS在多倍体和杂交物种中复杂的进化机制，因此ITS序列在温带竹子支系系统重建中需谨慎使用。 3. 低拷贝核基因GBSSI结果与分析 基于温带竹子支系的17属71种的408个序列进行了最大简约法和贝叶斯分析，结果表明，GBSSI基因在多倍体的温带竹子支系中为单拷贝；温带竹子支系为单系发生，筱竹属复合群，青篱竹亚族和倭竹亚族均不是单系，箬竹属、赤竹属、短枝竹属、巴山木竹属为多系，刚竹属、苦竹属、玉山竹属、箭竹属、筱竹属等为并系或者多系。据此，我们推测温带竹子支系内可能存在复杂的网状进化关系，其中17个种可能为异源四倍体起源，2种可能为异源六倍体起源；支持温带竹子支系的染色体基数为12。此外，对单拷贝核基因在多倍体基因组内的进化及其对系统重建的影响进行了初步讨论，并对温带竹子支系进一步深入研究进行了展望。 4. 温带竹子支系与分子进化速率 综合叶绿体八个非编码区片段、核核糖体rDNA ITS和GBSSI数据，温带竹子支系遗传分化较低，基因树枝长较短，分子进化速率较低。分析其原因可能主要有两个方面，一是竹子独特的生活史，世代交替时间通常为15-60年；二是与竹子的起源时间和快速辐射分化相关。可能正由于其生活史特别长，加之快速辐射分化、杂交、多倍化等等以及由此导致的DNA片段进化速率较低，使得温带竹子支系成为系统发育研究特别困难的类群。 |
| 英文摘要 | 1. Results and analyses of combined data of eight non-coding loci of the chloroplast genome We produced 8927 bp of sequences from eight non-coding chloroplast regions for a very broad sampling of representatives: 68 species in 18 genera with 2 outgroups. Phylogenetic analyses using maximum parsimony and Bayesian inference supported the temperate bamboos as a monophyletic group. The two major subtribes, Arundinariinae and Shibataeinae based on different inflorescence types were again proved to be polyphyletic. The cladograms suggested that Ferrocalamus was monophyletic, while Indocalamus, Sasa and Gelidocalamus were showed to be polyphyletic. Bashania, Pleioblastus and other 11 genera were proved to be paraphyletic or polyphyletic. Our analyses implied: (1) Using multiple loci chloroplast sequences could still not resolve the in-depth phylogenetic relationships within the temperate bamboo clade. (2) Extensive sampling was indispensable for the temperate bamboo clade, as most genera in the clade have not been proved to be monophyletic. 2. Results and analyses of nrDNA ITS sequences Based on molecular clone and sequencing analyses, a total of 116 distinct clone sequences representing 61 species of 16 genera of the temperate bamboo clade, were obtained and used in the gene genealogy analysis. Our results suggested an incomplete concerted evolution of this locus in some species of the temperate bamboo clade. The evolution pattern and evolution rates of ITS in intergeneric and congeneric species were different. Comparisons with the sequences length, GC-content, base changes, long terminal branch length in gene tree, the clone sequence Sasa shimidzuana_1 was identified as a pseudogene. From the short branch length, and low genetic differentiation, it suggested that the temperate bamboo clade was a group with a rapid evolutionary diversification. Polyploidization and hybridization had played an important role in the species evolution. 3. Results and analyses of a low-copy nuclear GBSSI gene sequences A nuclear low-copy gene phylogeny provided strong evidence for the hybrid origin of nineteen polyploidy species in the temperate bamboo clade. We cloned and sequenced about 1.4 kilobases of GBSSI gene from 71 species representing 17 genera of the temperate bamboo clade. Each of the two (three) loci in one species formed a separate group, which were more closely related to copies in other species than they are to each other. It is indicated that 17 species were allotetraploids, while 2 species were hexaploids. Phylogenetic analyses using maximum parsimony and Bayesian inference again supported temperate bamboos as a monophyletic group. The two subtribes, Arundinariinae and Shibataeinae were again proved to be polyphyletic. The cladograms suggested that Indocalamus, Sasa, Bashania and Gelidocalamus were polyphyletic. Phyllostachys, Pleioblastus, Yushania, Fargesia and Thamonocalamus, as currently defined, were proved to be paraphyletic or polyphyletic. We discussed the molecular evolution of a single-copy gene in an allopolyploid species. It is necessary for finding other low-copy nuclear genes to elucidate the origin and evolution of the temperate bamboo clade. 4. Molecular evolutionary rates in the temperate bamboo clade The combined analyses of eight chloroplast non-coding regions, nrDNA ITS and GBSSI sequences data implied that the temperate bamboo clade had slow molecular evolutionary rates with short branch length and low genetic divergence. The results probably attributed to two main factors. One is related to the very long life history of 15-60 years. Other one is the relatively late time of origin and subsequently radiative speciation. |
| 语种 | 中文 |
| 公开日期 | 2011-10-25 |
| 页码 | 135 |
| 源URL | [http://ir.kib.ac.cn/handle/151853/270]  |
| 专题 | 昆明植物研究所_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 | 曾春霞. 多DNA片段探讨温带竹子的系统发育和网状进化-以箬竹属、铁竹属和赤竹属为主[D]. 昆明植物研究所. 中国科学院昆明植物研究所. 2009. |
入库方式： OAI收割
来源：昆明植物研究所
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