Dissertation Research: Patterning of Morphological Diversification: Evolution of Floral Form in Tribe Amorpheae (Fabaceae)

9902206 Hufford和McMahon理解生物群之间形态多样性的模式是系统学的一个关键方面。在12，000种豆科蝶形花科中，豌豆状的花是高度保守的;但在新世界部落Amorpheae（包括Dalea属的“草原三叶草”）中，花的形式是高度修饰的，并且通常在形状或发育上不像豌豆。为了了解Amorpheae植物多样性的历史起源，研究生Michelle McMahon在华盛顿州立大学的顾问Larry Hufford博士的指导下，将分析部落中物种之间的历史关系（代表性分类群的系谱或亲缘关系），重点是叶绿体matK基因的DNA测序作为主要证据来源。此外，一个彻底的形态计量学研究将花的形式，以准确地评估花瓣和雄蕊的结构相似性，并建立分类群之间的变化的全部范围和分布。 将采取两种方法来综合植物的多样性和花型的多样性。首先，发育数据结构相似（同源）的花部分，分析的背景下，分子系统发育框架，可以提供有关的进化转型参与不同的成人形式的起源的见解。第二，详细的测量数据的关键花器官映射到一个单基因型可以与空模型的花性状的进化变化进行比较，以确定独特的，以及反复出现的模式的字符组合或趋势。系统发育和发育数据的综合应有助于解释花的形式在Amorpheae，模式，可能是由于成人和早期阶段的字符之间的相关性，加速进化的速度，或通过新的组合的反复出现的功能进化。拟议的工作将提供技术，彻底分析花的形式演变和了解如何模式的多样性之间的谱系发生在Amorpheae。

9902206Hufford and McMahon Understanding patterns of morphological diversity among groups of organismsis a key aspect of systematics. Among the 12,000 species of the legume subfamily Papilionoideae, pea-like flowers are highly conserved; but in the New World tribe Amorpheae (including "prairie clovers" of the genus Dalea) flower forms are highly modified, and often not pea-like in shape or development. To understand the historical origins of this floral diversity in Amorpheae, graduate student Michelle McMahon, under the direction of adviser Dr. Larry Hufford at Washington State University, will be analyzing the historical relationships (the genealogy or phylogeny of representative taxa) among species in the tribe with emphasis on DNA sequencing of the chloroplast matK gene as main source of evidence. In addition, a thorough morphometric study will be made of floral forms to assess accurately structural similarities in petals and stamens and to establish the full range and distribution of variation among taxa. Two approaches will be taken to synthesize phylogeny and diversity of floral form. First, developmental data for structurally similar (homologous) flower parts, analyzed in the context of the molecular-phylogenetic framework, can provide insights about the evolutionary transformations involved in the origin of disparate adult forms. Second, detailed measurement data of key floral organs mapped onto a phylogeny can be compared with null models of evolutionary change in floral characters, in order to determine unique as well as recurring patterns of character combinations or trends. A synthesis of phylogenetic and developmental data should help to explain patterns of floral form in Amorpheae, patterns that may be due to correlations between adult and early-stage characters, to accelerated rates of evolution, or to evolution through new combinations of recurring features. The proposed work will provide techniques for the thorough analysis of floral form evolution and an understanding of how patterning of diversity among lineages has occurred in Amorpheae.