Phylogeny and Evolution of Cornales: Integrating Molecules, Morphology, and Fossils

植物系统发育研究的最新进展表明，山茱萸和近亲(山茱萸目)代表着开花植物中最多样化和高度专业化的类群中的一个古老的进化谱系--类固醇类群。该目包含几个形态多样的家族，具有出色的化石记录，并为了解早期小行星的进化和多样化提供了一个特殊的系统。该项目的主要目标是利用来自广泛的DNA序列、形态和化石的证据重建Cornales的系统发育。系统发育将作为以下研究的基础：(1)该目成员之间的关键形态转变；(2)生物地理起源、洲际迁徙和主要角质谱系的辐射；以及(3)与形态分化和物种形成有关的分子进化模式和速度。系统发育还将提供一个框架，以预测和稳定的分类在山雀目内。玉米目植物是北半球森林中常见的乔木成分，被广泛种植用于观赏和药用。它们对森林生态至关重要，许多山茱萸树种在园艺中具有重要地位。它们在医学上也是相关的；例如，喜树是开花山茱萸的近亲，它含有一种天然抗癌药物(喜树碱)，在某些化疗治疗中被认为是仅次于紫杉醇的第二重要药物。一个强大的系统发育和预测和稳定的目分类将为指导这些植物的园艺、药理和其他生物学研究提供基础。研究中将收集的大量基因序列将对现有的被子植物分子数据集做出重大贡献，并将有助于在更高的分类水平上进行比较进化研究。此外，该项目还为研究生和本科生提供植物进化生物学和系统学方面的培训。最后，这个项目将为开花植物的“生命树”添加关键信息

Recent advances in plant phylogenetic studies revealed that the dogwoods and close relatives (order Cornales) represent an ancient evolutionary lineage within the most diverse and highly specialized group of flowering plants, the Asterid group. The order contains several morphologically diverse families with excellent fossil records and provides an exceptional system to understand the evolution and diversification of early asterids. The major goal of the project is to reconstruct the phylogeny of Cornales using evidence from extensive DNA sequences, morphology, and fossils. The phylogeny will serve as the basis for studies of: (1) key morphological transformations among members of the order; (2) biogeographic origin, intercontinental migration, and radiation of major cornalean lineages; and (3) pattern and rate of molecular evolution in relation to morphological differentiation and speciation. The phylogeny will also provide a framework for a predictive and stable classification within Cornales. Plants of Cornales are common tree elements in the forests of northern hemisphere and are widely cultivated for ornamental and medicinal uses. They are critically important to forest ecology and many dogwood species have great importance in horticulture. They also are medically relevant; for example, Camptotheca acuminata is a close relative of the flowering dogwoods and it contains a natural anti-cancer drug (camptothecin) that is considered second in importance to taxol for certain chemotherapy treatments. A robust phylogeny and predictive and stable classification of the order will provide a basis for directing horticultural, pharmacological, and other biological studies of these plants. The extensive gene sequences to be collected in the study will contribute significantly to the existing molecular datasets of angiosperms and will facilitate comparative evolutionary studies at higher taxonomic levels. Furthermore, the project provides training for graduate and undergraduate students in plant evolutionary biology and systematics. Finally, this project will add key information to the "Tree of Life" for flowering plants