Lycophytes, Bryophytes, and Charophytes: Testing Morphology and Molecule-Based Hypotheses

9408057来自细胞核和细胞器DNA的查普曼分子数据，与用于系统发育分析的数值算法相结合，使植物进化研究发生了革命性的变化。路易斯安那州立大学的拉塞尔·查普曼博士在将这些分子和分类方法应用于绿藻和所谓的低等陆地植物(如苔藓和球茎苔藓)分析方面处于领先地位。他主要专注于核核糖体基因序列，表明苔藓植物(苔藓、苔藓和角藻)虽然可能是陆地植物最早的分化谱系，但它们本身并不是一个单一的进化单位，而是一系列陆地“实验”。正在收集更多的DNA数据，以测试不同苔藓类群的系统发育亲缘关系，特别是评估目前将苔藓植物分类为17个不同亚目的实用性。随着样本的出现，分子分析也将应用于原始维管植物的相关群体，即石蒜(俱乐部苔藓和近亲)。与其他实验室正在进行的形态和超微结构研究相结合，查普曼博士对核糖体DNA进行的分子系统发育分析正在为植物适应陆地生活的变化提供方向和节奏的洞察。

9408057 Chapman Molecular data from nuclear and organellar DNA, in conjunction with numerical algorithms for phylogenetic analysis, have revolutionized the study of plant evolution. Dr. Russell Chapman of Louisiana State University has been a leader in the application of these molecular and taxometric methodologies to the analysis of green algae and of so-called lower land plants such as mosses and club-mosses. Focussing primarily on nuclear ribosomal gene sequences, he has shown that the bryophytes (mosses, liverworts, and hornworts), while likely to be the earliest diverging lineages of land plants, are themselves not a single evolutionary unit but a series of terrestrial "experiments." Additional DNA data are being collected to test the phylogenetic affinities of various bryophyte groups, and in particular to assess the utility of the current classification of mosses into 17 distinct suborders. As samples become available, molecular analyses will also be applied to related groups of primitive vascular plants, the lycophytes (club mosses and relatives). In association with morphological and ultrastructural studies underway in other laboratories, the molecular phylogenetic analyses of nuclear ribosomal DNA conducted by Dr. Chapman are providing insight to the direction and tempo of change in plants as they adapted to life on land.