RUI: Pollen Developmental Evolution in the Basalmost Angiosperms - Nymphaeales and Amborella

RUI：基部被子植物（睡莲目和安博拉目）的花粉发育进化

• 批准号: 0212521
• 负责人: Jeffrey Osborn
• 金额: $ 7万
• 依托单位: Truman State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-07-15 至 2004-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0212521&HistoricalAwards=false
• 关键词: RUI; Pollen; Developmental; Evolution; Basalmost

An understanding of the evolutionary relationships of flowering plants, or angiosperms, has been greatly improved in recent years, and water lilies (Nymphaeales) and Amborella have been identified as the earliest diverging lineages. Water lilies have a cosmopolitan distribution, comprise two families and eight genera, and have interested botanists for many years in part because they have characteristics of both major classes of flowering plants (dicots and monocots). Amborella includes a single species and is an understory shrub that is limited in geographic distribution to montane tropical rain forests in central New Caledonia. Comparative studies of pollen development in angiosperms are relatively rare, but make significant contributions to understanding the evolution of key characters, as well as evolutionary relationships, or phylogeny, when conducted. Relatively few pollen studies of water lilies and Amborella have been carried out, however. Historically, the pollen wall of water lilies has been reported as granular, a character state thought to be primitive among angiosperms, whereas that of Amborella has an unusual structure that does not appear to occur in other extant flowering plants. A recent study by the PI indicates that the mature pollen of all eight genera of water lilies is columellar, and that the developmental pattern and structure of these pollen wall elements makes them superficially resemble granules. The developmental pattern of these elements and that of other pollen characters in Nymphaeales and Amborella, however, are not well understood. Given the evolutionary importance of these two primitive groups, the overall focus of the PI's research is to study pollen developmental evolution in Nymphaeales and Amborella. The principal objectives of the proposed project are to (1) provide a comprehensive investigation of pollen development in two key water lily genera (Cabomba and Nuphar) and (2) obtain preliminary results on other genera. The proposed research will build on new data from the PI's laboratory about mature pollen structure in all eight water lily genera, as well as pollen development in three (Cabomba, Nuphar, and Euryale). The research will use combined microscopical techniques, and it will yield data at a level of resolution that has not been documented before. The new data will provide the foundation to examine the patterns of pollen developmental evolution within a phylogenetic context and determine functional correlations between pollen developmental characters and pollination biology.

近年来，对开花植物或被子植物的进化关系的理解有了很大的提高，睡莲（睡莲目）和Amborella已被确定为最早的分歧谱系。睡莲有一个世界性的分布，包括两个科和八个属，并有兴趣的植物学家多年来，部分是因为他们有两个主要类别的开花植物（双子叶植物和单子叶植物）的特点。Amborella包括一个单一物种，是一种林下灌木，地理分布局限于新喀里多尼亚中部的山地热带雨林。 被子植物花粉发育的比较研究相对较少，但对理解关键性状的进化以及进化关系或亲缘关系做出了重大贡献。 然而，对睡莲和Amborella的花粉研究相对较少。历史上，睡莲的花粉壁被报道为颗粒状，这是被子植物中被认为是原始的特征状态，而Amborella的花粉壁具有不寻常的结构，似乎在其他现存的开花植物中没有出现。 PI最近的一项研究表明，睡莲所有八个属的成熟花粉都是柱状的，这些花粉壁分子的发育模式和结构使它们表面上类似于颗粒。然而，这些元素的发育模式和睡莲目和Amborella的其他花粉性状的发育模式还没有很好的理解。鉴于这两个原始群体在进化上的重要性，PI研究的总体重点是研究睡莲目和Amborella的花粉发育进化。 该项目的主要目标是：（1）提供两个主要睡莲属（Cabomba和Nuphar）花粉发育的全面调查;（2）获得其他属的初步结果。 拟议的研究将建立在PI实验室关于所有八种睡莲属的成熟花粉结构以及三种（Cabomba，Nuphar和Euryale）花粉发育的新数据基础上。 这项研究将使用综合显微技术，它将产生以前没有记录的分辨率水平的数据。 新的数据将提供的基础上，研究花粉发育进化模式的系统发育背景下，并确定花粉发育性状和授粉生物学之间的功能相关性。