Molecular Systematics of the Asteridae

菊科的分子系统学

• 批准号: 8717600
• 负责人: Jeffrey Palmer
• 金额: $ 12万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-01-15 至 1989-09-01
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8717600&HistoricalAwards=false
• 关键词: Molecular; Systematics; Asteridae

Dr. Jeffrey Palmer and colleagues at the University of Michigan are studying evolutionary relationships among flowering plants at two distinct taxonomic levels. At one level, they plan to investigate relationships among the 50 or so families that comprise the subclass Asteridae, the second largest subclass of dicots. Although Asteridae are generally considered to be the most highly advanced and recently evolved of dicots subclasses, outstanding questions and controversies remain concerning the relative placement and relationships of most of the families in this group. In addition, there are fundamental doubts about whether the group as a whole is a natural, monophyletic one or an assemblage of parallel derivatives. Palmer will address this controversy by constructing a detailed phylogeny for the subclass using recently developed techniques of molecular systematic analysis. He will examine the distribution within this group and determine the phylogenetic significance of a number of defined chloroplast DNA rearrangements. He will also examine sequence variation in the chloroplast gene encoding the large protein subunit of the key photosynthetic enzyme, ribulose bisphosphate carboxylase. The second set of studies involves construction of a detailed molecular phylogeny for genera and tribes of the family Solanaceae of subclass Asteridae. This will greatly aid our understanding of evolutionary trends and relationships in this, the economically most important family in the subclass and also one of its largest. Despite the wide range of studies conducted on the biology and systematics of this important group of plants, which includes such vital crops as potatoes, tomatoes, and chili peppers, fundamental disagreements still exist regarding taxonomic relationships in the family. Palmer's approach here will involve comparative mapping of chloroplast DNA restriction site mutations and computer-assisted construction of phylogenetic trees based on these chloroplast DNA mutations.

密歇根大学的杰弗里·帕尔默博士和他的同事们正在两个不同的分类水平上研究开花植物之间的进化关系。在一个层面上，他们计划调查组成双子叶植物第二大亚纲--Asteridae亚纲的大约50个家庭之间的关系。尽管Asteridae通常被认为是双子叶亚纲中最高级和最新进化的亚纲，但关于该类群中大多数科的相对位置和关系仍存在悬而未决的问题和争议。此外，对于这个群体作为一个整体是一个自然的、单系的群体，还是平行衍生品的集合，存在着根本的怀疑。帕尔默将利用最近发展起来的分子系统分析技术，通过构建亚纲的详细系统发育图来解决这一争议。他将研究这一组中的分布，并确定一些明确的叶绿体DNA重排的系统发育意义。他还将研究编码关键光合酶核酮糖二磷酸羧基酶的大蛋白亚基的叶绿体基因的序列变异。第二组研究包括构建菊科亚纲茄科的属和部落的详细的分子系统学。这将极大地帮助我们理解这个家庭的进化趋势和关系，这个家庭在经济上最重要，也是其最大的家庭之一。尽管对这一重要植物的生物学和系统学进行了广泛的研究，其中包括土豆、西红柿和辣椒等重要作物，但对于该科的分类关系仍存在根本分歧。帕尔默的方法将涉及叶绿体DNA限制位点突变的比较图谱，以及基于这些叶绿体DNA突变的计算机辅助构建系统发育树。