Molecular Systematics of the Asteridae

杰弗里·帕尔默博士和他的同事们 密歇根大学正在研究开花植物 植物在两个不同的分类水平。在一个层面上，他们计划 调查了50个左右的家庭之间的关系， 包括海星亚纲，海星的第二大亚纲 双子叶植物。虽然海星科通常被认为是 双子叶植物的最高级和最近进化的亚类， 关于这一问题，仍然存在一些悬而未决的问题和争议。 大多数家庭的相对位置和关系， 这群人此外，人们对以下问题存在根本性的怀疑： 无论该群体作为一个整体是一个自然的，单系的，或 平行导数的集合。帕默会解决这个问题 通过为该子类构建详细的系统发生学而引起的争议 利用最近开发的分子系统学技术， 分析.他将研究这一群体内的分布情况， 确定一些定义的系统发育意义 叶绿体DNA重排他还将检查序列 编码大蛋白的叶绿体基因的变异 关键光合酶核酮糖二磷酸亚基 羧化酶 第二组研究涉及构建一个 详细的科属和族的分子遗传学 菊科茄科。这将极大地帮助我们 了解进化的趋势和关系， 在子类中经济上最重要的家庭， 其中最大的。尽管进行了广泛的研究， 关于这一重要植物群的生物学和系统学， 包括土豆、西红柿和辣椒等重要作物 辣椒，基本的分歧仍然存在， 科中的分类学关系。帕默在这里的做法 将涉及叶绿体DNA限制的比较作图 位点突变和计算机辅助构建系统发育 基于这些叶绿体DNA突变的树木。

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.