Collaborative Research: Phylogeny and Evolution of American Taxa of Acacia Subgenus Acacia

相思属由灌木和乔木组成，在包括美洲在内的热带和亚热带世界的干旱植被中占主导地位。尽管相思树具有重要的经济和生态意义，但这数百个物种之间的进化关系(系统发育)和形态进化趋势(如叶、花和种子进化)却鲜为人知。伊利诺伊大学的大卫·塞格勒博士和爱荷华大学的约瑟夫·米勒博士将从来自美洲、非洲、亚洲和澳大利亚的大量相思物种样本中积累新的叶绿体和核基因DNA序列数据。在墨西哥和多米尼加共和国的实地工作将补充来自旧大陆物种的同事提供的样本，以构建以美洲相思亚属为主的系统发育框架，并探索与那些被怀疑为近亲的非洲物种的关系，包括一些与蚂蚁的共生关系与美国蚂蚁-相思共生体非常相似的物种。反过来，系统发育框架将有助于澄清有关物种划界、地理分布和组内命名的问题。加深对相思树系统学和系统发育的了解将有助于农学家、自然资源保护者、生态学家和牧场管理者的工作，并将突出这些植物的传粉生物学、根瘤菌固氮和生物地理学方面的问题。将加强与拉丁美洲、非洲、澳大利亚和欧洲的科学同行的互动。学生将接受实地和实验室(植物标本馆)研究方面的培训，并将陪同调查人员到国外进行实地采集旅行。交互式识别密钥将被发布到一个由澳大利亚研究人员维护的网站上，用于研究相思生物学和进化。

0414902Miller The genus Acacia consists of shrubs and trees that are dominant in the arid vegetation of the tropical and subtropical world, including the Americas. Despite economic and ecological importance of acacias, the evolutionary relationships of the species (phylogenies) and morphological trends of evolution among the hundreds of described species (such as leaf, flower, and seed evolution) are poorly known. Collaborating researchers Dr. David Seigler at University of Illinois and Dr. Joseph Miller at University of Iowa will accumulate new DNA sequence data for plastid and nuclear genes from numerous species samples of acacias from the Americas, Africa, Asia, and Australia. Field work in Mexico and the Dominican Republic will complement samples supplied by colleagues from Old World species, to construct a phylogenetic framework for the largely American subgenus of acacias, and to explore relationships with those African species suspected to be close relatives, including some with symbiotic associations with ants remarkably similar to the American ant-acacia symbionts. In turn, the phylogenetic framework will help clarify issues concerning species delimitation, geographic distribution, and nomenclature in the group. Improved understanding of the systematics and phylogenetics of acacias will help agronomists, conservationists, ecologists, and rangeland managers in their work, and will sharpen questions to be addressed concerning pollination biology, rhizobial nitrogen fixation, and biogeography of these plants. Interactions will be strengthened with scientific colleagues in Latin America, Africa, Australia, and Europe. Students will be trained in field and laboratory (herbarium) studies, and will accompany the investigators on field collecting trips abroad. Interactive identification keys will be posted to a website maintained by Australian researchers for the study of acacia biology and evolution.