A Phylogenetic Analysis of the Monocots Based on Molecular and Morphological Character Sets

摘要单子叶植物是开花植物（被子植物）的主要类群之一。这是一个多样化的群体，大约有6万种，包括禾本科植物（小麦、玉米、水稻和它们的许多野生近亲）、棕榈树和兰花。尽管单子叶植物群被广泛认为是开花植物中的一个自然（单系）谱系，但该群体中主要谱系分化历史的许多方面仍然不清楚。对几个主要谱系的支持已经很好地建立起来（例如，Poales目，包括草和它们的亲戚，Zingiberales目，包括姜、香蕉和它们的亲戚），但是在其他高级的单子科分类中存在重大差异。基于形态学变化和各种分子特征的系统发育分析产生了相互矛盾的结果，戴维斯博士的研究将使用“总证据”进行调查，其中将收集多个典型物种的字符集；这些数据将被合并成一个数据集，并作为一个整体进行分析。需要分析的数据集包括：1)形态学，包括解剖特征、花粉结构和种子发育；2)叶绿体（rbcL）和线粒体（atpA）基因的DNA序列变异；3)其他合作研究人员生成的额外特征集。

9727000 Davis A PHYLOGENETIC ANALYSIS OF THE MONOCOTS BASED ON MOLECULAR AND MORPHOLOGICAL CHARACTER SETS The monocotyledons are one of the major groups of flowering plants (angiosperms). This is a diverse group of about 60,000 species that includes the grasses (wheat, maise, rice, and their many wild relatives), palms, and orchids. Although the monocot group is widely recognized as a natural (monophyletic) lineage within the flowering plants, many aspects of the history of divergence of the principal lineages within this group remain obscure. Support for several major lineagess is well established (e.g., the order Poales, which includes grasses and their relatives, and the order Zingiberales, which includes the gingers, the bananas, and their relatives), but there are major differences in the other higher-level groupings recognized by various comprehensive accounts of the monocots. Phylogenetic analyses based on variation in morphology and a variety of molecular characteristics, have yielded conflicting results which Dr. Davis' study will investigate using "total evidence" in which multiple character sets will be collected for exemplar species; these will be combined within a single data set and analyzed as a unit. Data sets to be analyzed include 1) morphology with features of anatomy, pollen structure, and seed development included, 2) DNA sequence variation from genes of the chloroplasts (rbcL) and mitochondria (atpA), and 3) additional character sets being generated by other cooperating investigators.