Angiosperm Phylogeny: Evidence From rbcL, 18S rDNA, and atpB

被子植物（开花植物）是世界上最大和最具经济价值的陆地植物组合，有30多万种。各种各样的被子植物形式出现在1亿多年前的化石记录中，许多其他物种似乎在这个组合的起源之后迅速出现。然而，尽管付出了巨大的努力，我们对被子植物类群之间关系的理解仍然很不完整，特别是在被子植物多样化早期出现的类群之间。博士提出的研究。Soltis和Soltis将有助于澄清被子植物主要类群之间的系统发育关系，也许更重要的是，有助于确定该组合中最古老成员之间的关系。后者在提供对多样化的形式和比率作出新的解释的基础方面将证明是特别重要的。这项工作将需要从三个不同的基因（rbcL， 18S rDNA和atpB）中获取DNA序列，这些基因将用于推断大约400种被子植物物种之间的关系，这些被子植物物种被选为所有主要被子植物物种群体的代表。这项工作最终将导致开花植物的新分类，这将更准确地反映历史和谱系关系。该项目还将带来新的分析方法，用于推断涉及大量物种的超大数据集的家谱。

9707868 SOLTIS The angiosperms (flowering plants) represent the largest and most economically-important assemblage of land plants in the world, there being over 300,000 different species. Diverse angiosperm forms appear in the fossil record a little over 100 million years ago, and many additional species appear to have arisen rapidly following the origin of the assemblage. However, despite extensive effort, our understanding of relationships among angiosperm groups remains far from complete, especially among groups that arose early during angiosperm diversification. The research proposed by Drs. Soltis and Soltis will help clarify phylogenetic relationships among major groupings of angiosperms, and perhaps more importantly, help identify relationships among the most ancient members of the assemblage. The latter will prove especially critical in providing the basis for new interpretations of the patterns and rates of diversification. The work will entail acquisition of DNA sequences from three distinct genes (rbcL, 18S rDNA, and atpB) that will be used to infer relationships among roughly 400 angiosperm species that were selected as representatives of all major groups of angiosperm species. The work ultimately will lead to a new classification of flowering plants that will reflect more accurately both historical and genealogical relationships. The project also will lead to new analytical methods for inferring family trees that involve extremely large data sets for large groups of species.