Chloroplast DNA Phylogeny of Basal Angiosperms

9727025 Olmstead 奥姆斯特德博士的研究将解决一个困扰植物学家几百年的问题：开花植物（被子植物）早期多样化的模式。 这项研究项目应该有助于我们了解这些植物可能看起来像什么，以及花和营养特征的进化过程可能采取了什么样的方式。 在许多方面，这是显花植物系统学中最大的问题。 之前三项基于DNA的研究检查了单个基因，得出了相互矛盾的结果，或者无法解决大约1亿年前分化的血统的现存代表之间的关系。 实验方法将是确定17个叶绿体基因的DNA序列，总计约13,000个核苷酸的约50种植物中的每一种选择代表先前确定的关键谱系的基础被子植物。 这一办法将使目前可用于帮助解决问题的数据增加三倍，应足以产生解决办法。 研究所需的大部分材料已经收集，并将通过与其他研究人员和植物园馆长的合作来实现更多的采样。

9727025 Olmstead Dr. Olmstead's research will address a problem that has confounded botanists for several hundred years: the pattern of early diversification of flowering plants (angiosperms). This research project should help us to understand what these plants may have looked like and what course of evolution in floral and vegetative features may have taken. In many respects this is the greatest question in flowering plant systematics. Three prior DNA-based studies examining individual genes have yielded conflicting results or have been unable to resolve relationships among the extant representatives of lineages that were diverged approximately 100 million years ago. The experimental approach will be to determine DNA sequences for 17 chloroplast genes totaling approximately 13,000 nucleotides for each of approximately fifty plant species chosen to represent previously identified critical lineages of the basal angiosperms. This approach will provide a three-fold increase in the data currently available to help solve the problem and should be sufficient to produce resolution. Much of the required material for the research has already been gathered, and additional sampling will be achieved by cooperation with other researchers and curators at botanical gardens.