Phylogeny and Evolution of the Basal Genera of Mimosoid Legumes

[129228] lucow尽管拟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的豆类类群，拟豆科植物和拟豆科植物，对它们的研究还很不足。最近的豆科进化研究仅纳入了来自约4000种拟虫类动物的7个样本。康奈尔大学的Melissa Luckow博士和他的同事们提出的工作旨在通过深入研究含蝇亚科的属来纠正这种不平衡。具体而言，本研究的目标是：1)利用形态学和DNA序列（来自核和质体基因）的数据构建39属豆科植物的进化树；2)编写这些属的修订，完成鉴定关键字和详细描述。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。分子和形态数据将用于系统发育分析，以澄清属之间的关系，并阐明与适应干旱气候有关的固氮和特征的演变。交互式键和描述将被构建并纳入生命多样性网站。豆科植物是第三大开花植物科，对人类的经济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和用材树特别重要，为世界边缘和干旱地区提供木材和饲料。目前正在花费大量精力改进和开发豆科植物、金合欢和Leucaena在干旱生境中的食物和饲料。然而，目前关于与Prosopis最接近的亲戚是什么，或者是否所有新大陆的金合欢物种都与非洲和澳大利亚的金合欢物种有关的信息很少。系统发育背景对这些属的物种的农业评价和开发是必不可少的；具有全面描述的可靠的属识别钥匙将被分类学家、林业学家、植物育种家和生态学家广泛使用。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被研究的群体之一，因为这个家族是如此庞大和多样化。创建可下载的基于网络的密钥和描述将确保发展中国家的用户广泛获得和负担得起。这种格式也将使教师更容易将材料整合到他们的课堂中。

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.