Dissertation Research: Phylogenetic and Molecular Evolutionary Studies of the Tageteae (Asteraceae)

9411536简森在过去几年里，利用脱氧核糖核酸数据研究生物体之间的系统发育或系谱关系的情况急剧增加。对于大多数植物群来说，出于几个方法论的原因，重点一直放在叶绿体中的细胞器DNA上。因此，一个主要的问题是，叶绿体DNA的突变差异是否与植物物种之间的核DNA突变差异密切相关，这通常更难分析。研究生丹尼斯·卢克曼在德克萨斯大学教授顾问罗伯特·詹森的指导下，在对一大群向日葵近亲Tageteae的研究中解决了这个问题。他将分析来自叶绿体和核DNA组的大量数据，比较物种之间的突变差异模式，并重建这组开花植物的系统发育树。分子研究的结果将与传统的形态特征相结合，以改进这些植物的分类并指定可靠的鉴定特征。对一大群向日葵近缘植物Tageteae的细胞器和核来源的DNA数据进行分析，并结合形态特征，将有助于提高对这些植物的分类和系统发育的了解。

9411536 Jansen The use of DNA data in studying the phylogenetic or genealogical relationships among organisms has increased dramatically over the last few years. For most plant groups, the focus, for several methodological reasons, has been upon organellar DNA from the leaf chloroplast. Consequently, a major question is posed concerning whether mutational differences in chloroplast DNA are strongly correlated with mutational differences between plant species in their nuclear DNA, which is usually more difficult to analyze. Graduate student Dennis Loockerman, under the supervision of faculty adviser Robert Jansen at the University of Texas, is addressing this question in his study of a large group of sunflower relatives, the Tageteae. He will be analyzing large amounts of data from both chloroplast and nuclear DNA sets, comparing patterns of mutational differences among species, and reconstructing phylogenetic trees for this group of flowering plants. Results from the molecular studies will be integrated with traditional morphological characters, to improve classification of these plants and designate reliable identification features. Analysis of DNA data from both organellar and nuclear sources in a large group of sunflower relatives, the Tageteae, and integration with morphological characters, will improve taxonomic and phylogenetic understanding of these plants.