DISSERTATION RESEARCH: Systematic Biology of Costaceae(Zingiberales): Using Molecular and Morphological Data to Investigate Phylogenetics and Floral Evolution

已向Dennis Wm博士颁发了一笔赠款。史蒂文森、W·约翰·克雷斯和切尔西·D·斯佩克特在纽约植物园开展研究，研究Costaceae的系统学和进化。Costaceae是一个热带植物科，约有130个物种，与经济上重要的香蕉和生姜以及重要的观赏植物如螺旋藻和Strelitzia(天堂鸟)关系密切。Costaceae也以其观赏吸引力而闻名，它有艳丽的花和花的结构，其形状和颜色与传粉者的吸引密切相关。这项拟议的研究旨在确定该科物种之间的进化关系，并调查Costaceae达到当前多样性水平的历史背景。将为75个物种生成约2500kb的DNA序列数据，以代表该科内的花卉和生物地理多样性。这些数据将与形态特征数据一起使用现代系统发育技术进行分析。此外，还将研究不同花朵形状的发育，以确定花朵形状进化的潜在机制。刺果属中的某些物种通过蜂鸟授粉，而其他物种则由蜜蜂授粉。因此，根据这些总体的花特征，该属被分为两个组，然而最近的证据表明，这些组不能反映进化史。相反，似乎个人可以在蜂鸟和蜜蜂授粉之间来回切换，这可能是基于环境条件，如传粉者的可用性或有效性。由于在南美洲和非洲物种中发现了相似的花型，可以得出结论，在这些地理上遥远的森林中存在常见类型的授粉压力，在不同的植物谱系中产生相似的形状和颜色。这项研究将增加我们对促进热带植物物种形成和多样性的力量的理解。此外，花发育研究可能有助于表明遗传因素如何参与多种形式的进化，从而使人们更清楚地了解生物多样性的遗传基础。

A grant has been awarded to Drs. Dennis Wm. Stevenson, W. John Kress, and Chelsea D. Specht at the New York Botanical Garden to study the systematics and evolution of Costaceae, a tropical plant family of approximately 130 species closely related to the economically important bananas and gingers as well as prominent ornamentals such as Heliconia and Strelitzia (Bird-of-Paradise). Also known for their ornamental appeal, Costaceae have showy flowers and floral structures with shapes and colors that are closely linked to the attraction of pollinators. The proposed research is designed to determine evolutionary relationships among species within the family and investigate the historical context in which Costaceae has achieved its current level of diversity. Approximately 2500kb of DNA sequence data will be generated for 75 species chosen to represent floral and biogeographic diversity within the family. These data will be analyzed along with morphological character data using contemporary phylogenetic techniques. In addition, the development of the different floral shapes will be studied to determine potential mechanisms involved in the evolution of floral form.Certain species in the genus Costus are pollinated by hummingbirds, while others are bee-pollinated. The genus has thus been divided into two groups based on these overall floral characteristics, however recent evidence has shown that these groupings are not reflective of evolutionary history. Rather, it seems as though individuals can switch back and forth between hummingbird and bee pollination, possibly based on environmental conditions such as pollinator availability or efficacy. Since similar floral forms are found in South American and African species, it may be concluded that common types of pollination pressures occur in these geographically distant forest, yielding similar shapes and colors in distinct lineages of plants. This study will increase our understanding of the forces that promote speciation and diversity in tropical plants. In addition, floral development studies may help to indicate how genetic factors are involved in the evolution of diverse forms, leading to a clearer understanding of the genetic basis for biodiversity.