Phylogeny and Evolution of the Basal Genera of Mimosoid Legumes

0129228 Luckow虽然含羞草豆科植物是热带森林的重要组成部分，特别是在干旱和半干旱地区，但相对于其他两个主要豆科植物群，蝶形（豌豆花）和caesalpinioid豆科植物，它们的研究还不够。最新的豆科植物进化研究仅纳入了来自估计4000种含羞草的7个样本。康奈尔大学的梅丽莎卢科博士及其同事提出的工作旨在通过对含羞草亚科属的深入研究来纠正这种不平衡。具体来说，本研究的目标是：1）构建一个进化树的39属含羞草豆科植物的形态和DNA序列（从核和质体基因）的数据，和2）写一个修订这些属，完成识别和详细描述的关键。野外工作将在非洲、马达加斯加和南美洲收集稀有和不寻常的物种。分子和形态学数据将用于系统发育分析，以澄清属之间的关系，并阐明固氮的进化和与适应干旱气候有关的特征。互动的关键和描述将被构建并纳入生命多样性网站。 豆科植物是第三大花卉植物家族，在经济上对人类的重要性仅次于禾本科植物。含羞草在热带生态系统中作为农林业和木材树木特别重要，为世界边缘和干旱地区提供木材和饲料。目前，人们正在努力改进和开发牧豆树、金合欢和银合欢等树种，以在干旱生境中作为食物和饲料。然而，目前几乎没有关于与牧豆树最近的亲戚可能是什么的信息，或者是否新大陆的所有金合欢物种都与非洲和澳大利亚的金合欢物种有关。一个系统发育的背景下，将是不可或缺的农业评估和发展的物种在这些属，可靠的识别关键属，全面的描述，将被广泛使用的分类学家，林业，植物育种，生态学家。例如，拉丁美洲的大多数地区缺乏全面的植物区系;豆科植物也往往是最后一组工作，因为家庭是如此之大和多样化。创建可下载的网上检索表和说明，将确保发展中国家用户广泛获得和负担得起。这种格式也将使教师很容易将材料融入他们的课堂。

0129228Luckow Although the mimosoid legumes are an important component of tropical forests, especially in arid and semiarid regions, they have been understudied relative to the two other major legume groups, the papilionoid (pea-flowered) and caesalpinioid legumes. The most recent evolutionary study of the legume family incorporated only 7 samples from an estimated 4000 species of mimosoids. Proposed work by Dr. Melissa Luckow at Cornell University and colleagues is aimed at correcting the imbalance by intensive study of genera in the subfamily Mimosoideae. Specifically, the goals of this study are: 1) to construct an evolutionary tree for 39 genera of mimosoid legumes using data from both morphology and DNA sequences (from nuclear and plastid genes), and 2) to write a revision of these genera, complete with keys for identification and detailed descriptions. Field work will be undertaken to collect rare and unusual species in Africa, Madagascar, and South America. Molecular and morphological data will be employed in a phylogenetic analysis that will clarify the relationships among the genera and shed light on the evolution of nitrogen-fixation and characters associated with adaptation to arid climates. Interactive keys and descriptions will be constructed and incorporated into the Diversity of Life web site. The legume family is the third largest flowering-plant family, and second only to grasses in economic importance to mankind. The mimosoids are particularly important in tropical ecosystems as agroforestry and timber trees, providing wood and forage in marginal and arid regions of the world. Much effort is currently being expended to improve and exploit species of Prosopis (mesquite), Acacia, and Leucaena for food and fodder in arid habitats. Yet, currently there is little information on what the closest relative to Prosopis might be, or whether or not all species of Acacia in the New World are related to those in Africa and Australia. A phylogenetic context will be indispensable to the agricultural evaluation and development of species in these genera; reliable identification keys to the genera, with comprehensive descriptions, will be widely used by taxonomists, foresters, plant breeders, and ecologists. For example, most areas in Latin America lack comprehensive floras; legumes also tend to be one of the last groups to be worked on since the family is so large and diverse. Creating web-based keys and descriptions that can be downloaded will insure wide availability and affordability to users in developing countries. This format will also make it easy for instructors to integrate the material into their classrooms.