Dissertation Research: Phylogeny and Character Evolution in Yucca L. Based upon Morphological and Molecular Analyses

在德克萨斯大学指导老师Beryl Simpson的指导下，研究生Karen Clary正在研究沙漠属丝兰的分类学和系统发育。据估计，在墨西哥和美国大约有35种丝兰。形态学、解剖学和分子（DNA）分析正在进行中，以便为评估系谱亲缘性提供比较数据。核糖体DNA重复序列的内部转录间隔区将被测序，以确定物种之间核苷酸组成的突变差异。核DNA分析的结果将与基于同一物种叶绿体DNA研究的结果进行比较。分子和形态特征将结合起来，以实现可靠的植物分类。了解丝兰的分子和形态特征的多样性模式将提供关于该属的起源及其与沙漠条件有关的进化的答案，总的来说，特别是当与丝兰蛾（这些植物的主要传粉者）的系统发育数据进行比较时，应该证明是有趣的。

9410882 Simpson Graduate student Karen Clary, under the supervision of faculty adviser Beryl Simpson at the University of Texas, is studying the taxonomy and phylogeny of the desert genus Yucca, estimated to encompass ca. 35 species in Mexico and the U.S. Morphological, anatomical, and molecular (DNA) analyses are being conducted to provide comparative data for assessing genealogical affinities. The internal transcribed spacer region of the nuclear ribosomal DNA repeat will be sequenced to determine mutational differences in nucleotide composition among species. Results from nuclear DNA analyses will be compared to those based upon chloroplast DNA studies for the same species. Molecular and morphological characters will be combined to achieve a reliable classification of the plants. An understanding of patterns of diversity in molecular and morphological features in Yucca will provide answers about the origin of the genus and its evolution in relation to desert conditions, in general, and in particular should prove interesting when compared with phylogenetic data on yucca moths, the chief pollinators of these plants.