【作者】 薛华杰；

【导师】 吴国荣；

【作者基本信息】 南京师范大学 ， 植物学， 2007， 硕士

【摘要】 本论文采用PCR直接测序的方法，基于ITS序列，应用序列特征、遗传距离与系统树分析等方法对东亚广义当归属(Angelica s．l．)的系统关系进行重建，主要探讨了狭义当归属(Angelica s．s．)及其近缘属之间的关系，并且重点研究了当归属和独活属(Heracleum L．)之间的关系，法落海(Anegelica apaensis／Heracleum apaense)、紫花前胡(Angelica decursiva／Peucedanum decursivum)等的系统位置及其归属。主要研究内容和结果如下：1．东亚当归属植物的分类学研究测定了东亚地区狭义当归属及其近缘共7属40种代表植物的核糖体DNA ITS序列，并结合GenBank中相关植物的ITS序列(含外类群3种)对东亚地区狭义当归属植物内部以及当归属与其近缘属植物之间的亲缘关系进行了分析。结果表明：(1)广义当归属中的狭义当归属、柳叶芹属(Czernaevia Turez．)和高山芹属(Coelopleurum Ledeb．)之间的亲缘关系较近，山芹属(Ostericum Hoffm．)与它们的亲缘关系较远，这与果实形态、化学分析的结果一致，建议将山芹属作为一个相对独立的分类群处理。(2)ITS序列分析结果支持狭义当归属不是单起源的自然分类群，而应该被分成若干组的观点。(3)ITS序列以及化学成分分析结果表明，前胡属(Peucedanum L．)与狭义当归属之间的亲缘关系很近。(4)形态、化学成分以及ITS等多方面分析结果显示，当归(A．sinensis)与狭义当归属的多数植物之间均有一定的差距，其归属问题值得商榷。(5)ITS序列与化学成分的分析结果均显示藁本属(Ligusticum L．)不是一个自然类群。2．法落海的系统分类学地位测定了法落海以及当归属和独活属共12种代表植物的核糖体DNA ITS序列，并结合GenBank中独活属4种代表植物的ITS序列，以羌活属的羌活(Notopterygium incisum)作为外类群，对法落海的系统分类地位进行了分析。结果表明，依据不同的ITS区序列会得出不同甚至截然相反的结论：若依据ITS1序列，法落海应该归属到当归属；若依据ITS2序列，法落海应该归属到独活属。进一步分析法落海与当归属、独活属植物ITS区序列的碱基组成时发现，法落海在ITS1区拥有当归属植物的序列特征，而其ITS2区拥有独活属植物的序列特征。综上分析，支持法落海是介于当归属与独活属之间的一个过渡分类群的系统分类观点。3．当归属和前胡属(Peucedanum L．)之间的亲缘关系以及紫花前胡的系统分类地位测定了当归属、前胡属等2属23种代表植物的核糖体DNA ITS序列，并结合GenBank中2属6种的ITS序列，以羌活属的羌活作为外类群，对当归属、前胡属之间的亲缘关系及紫花前胡的系统地位进行了研究。结果表明：(1)当归属与前胡属的亲缘关系很近；(2)结合形态学与化学等其他学科证据支持将紫花前胡归属到当归属。本论文还总结了广义当归属分类学研究历史和现状，概括了用于植物分子系统学研究的各类分子标记及其研究方法。更多还原

【Abstract】 In order to resolve the relationships among species from Angelica s.s. and its allied genera in East Asia, ITS (Internal Transcribed Spacer) sequences were used to analyze their sequence divergences and to construct three phylogenetic trees in this paper. In addition, the relationship between Angelica L. and Heracleum L. was studied and the phylogenetic position of Angelica apaensis/Heracleum apaensh and Angelica decursiva/Peucedanum decursivum were analyzed. The results were summarized as follows:1. Taxonomic study of Angelica L. from East AsiaIn order to resolve the relationships among species from Angelica s.s. and its allied genera in East Asia, ITS sequences of 44 taxa representing these genera were used to analyze. Three taxa were used as the outgroup. Some deductions could be achieved as follows. (1) The relationship among the three genera Angelica s.s., Czernaevia Ledeb. and Coelopleurum Ledeb. was close, but the relationship between Ostericum Hoffm. and any genus from Angelica s.l. was far. It was also supported by analyses on fruit anatomy and chemical constitutes. Ostericum L. was proposed as a relatively independent genus. (2) Angelica s.s. was proved not to be monophyletic and it should be divided into several sections. (3) Both results from ITS sequences and chemical constitutes indicated that the relationship between Peucedanum L. and Angelica s.s. was very close. (4) Results from ITS sequences as well as from conformation and chemical constitutes showed that the divergence of A. sinensis from other taxa of Angelica s.s. was great. The taxonomic position of A. sinensis should be reconsidered. (5) Both analyses of ITS sequences and chemical constitutes revealed that Ligusticum L. was not a natural group.2. Taxonomic Study of Angelica apaensislHeracleum apaensisIn order to resolve the phylogenetic position of A. apaensis, ITS sequences from A. apaensis and 16 other species in these two genera (4 of them were from GenBank) were used. Notopterygium incisum was used as the outgroup. Analysis on different ITS regions resulted in contradictory conclusions: analysis on ITS1 sequences indicated that A. apaensis should belong to Angelica L., while analysis on ITS2 sequence suggested that it belonged to Heracleum L.. Further studies demonstrated that A. apaensis possessed base sequence characters similar to plants in Angelica L. in ITS1 region, but had base sequence characters similar to plants in Heracleum L. in ITS2 region. Therefore, results of this study support the view that A. apaensis is a transitional taxon between Angelica L. and Heracleum L..3. Relationship between Angelica L. and Peucedanum L. and taxonomic study of Angelica decursiva/Peucedanum decursivumIn order to resolve the relationship between Angelica L. and Peucedanum L. and the phylogenetic position of Angelica decursiva/Peucedanum decursivum, ITS sequences from A. decursiva and 23 other species in these two genera (6 of them were from GenBank) were used. Notopterygium incisum was used as the outgroup. Results demonstrated that: (l)there was a relative close relationship between Angelica L. and Peucedanum L.; (2)being associated with results from morphology, chemistry and others, results in this paper supported the view that A. decursiva/P decursivum should be classified into Angelica L..The taxonomic history, current research situation of Angelica L. and the outline of many kinds of molecular markers used in plant phylogenetic studies were also summarized and discussed in this paper.更多还原