Phylogenetic Studies of DNA and Morphological Variation in the Subtribe Ecliptinae

系统的研究亚族Ecliptinae的部落 Heliantheae(菊科),一群大约500 - 600种 南部和东部美国、墨西哥、中美洲和南美洲,非洲 和亚洲。研究将集中在四个主要问题上：阐明主要谱系和亚部落内部的关系；阐明了太阳花科亚族中最复杂、分类难度最大的属Verbesina的近属分类；韦尔贝斯人的属类关系解析和亚部落安置；以及对南美韦尔贝西纳的进化和辐射模式的研究。这些目标将主要通过收集叶绿体和核糖体DNA限制性位点数据以及染色体和形态数据来实现。对这些不同的数据集进行进化分析，将产生一个亚部落和部落Heliantheae中最大的属的系统发育。这些研究的结果，结合最近对ÕHeliantheae的cpDNA限制性位点研究（Kim et al. 1990a），将有助于澄清菊科最大的一个部落的亚部落界限和关系。此外，在Verbesina的次属水平上，由此产生的系统发育可以用来构建该属的现代次属分类，并为解决重要的生物地理学问题提供基础。

Systematic studies of the subtribe Ecliptinae of the tribe Heliantheae (Asteraceae), a group of about 500-600 species of the Southern and Eastern USA, Mexico, Central and South America, Africa and Asia are proposed. The study will focus on four major problems: elucidation of the major lineages and relationships within the subtribe; clarification of the infrageneric taxonomy of Verbesina, which is the most complex and taxonomically difficult genus of the subtribe and the largest genus of tribe Heliantheae; resolution of generic relationships and subtribal placement of Verbesian; and examination of the patterns of evolution and radiation of Verbesina in South America. These goals will be accomplished primarily be gathering chloroplast and nuclear ribosomal DNA restriction site data, as well as chromosomal and morphological data. Cladistic analysis of these diverse data sets will produce a phylogeny for the subtribe and the largest genus in tribe Heliantheae. The results of these studies, combined with recent cpDNA restriction site studies of the ÕHeliantheae (Kim et al. 1990a) will help clarify subtribal limits and relationships in one of the largest tribes of the Asteraceae. Furthermore, at the infrageneric level within Verbesina, the resulting phylogenies can then be used to construct a modern infrageneric classification of the genus, as well as provide a basis for resolving important biogeographical questions.