Phylogenetic status of Helicodictyon planctonicum and Desmochloris halophila gen. et comb. nov. and the definition of the class Ulvophyceae (Chlorophyta)
Phylogenetic status of Helicodictyon planctonicum and Desmochloris halophila gen. et comb. nov. and the definition of the class Ulvophyceae (Chlorophyta)
复制标题
Helicodictyon planctonicum 和 Desmolucris halophila gen 的系统发育状况。
DOI：
10.2216/i0031-8884-40-5-421.1
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发表时间：
2001
期刊：
影响因子：
1.6
通讯作者：
Fumiko Maiwa
中科院分区：
文献类型：
--
作者：
Shin Watanabe;Naoko Kuroda;Fumiko Maiwa
通过对Planctonicum的配子和盐生嗜盐绿僵菌游动孢子的电子显微镜观察，发现基体呈逆时针方向错开，并伴生十字形鞭毛小根系统，根生体内沿d小根延伸。在Planctonicum中，配子被形状不定的鳞片覆盖，两条平行的条纹连接每个基体的后侧，存在前基体，端帽与一个微管三联体相连。在盐生冬虫夏草中，游动孢子是裸露的，基体的前侧由基体之间重叠区域的矩形连接板连接，每个基体的近端被终端帽广泛覆盖。利用18S rDNA序列对43个分类群进行了分子系统发育分析，其中包括微小绿僵菌、毛状尿孢霉和硬管藻变种的新序列。Tenuis，此外还有H.planctonicum和C.Halophila。根据分子数据，灵芝属和斯图尔特属由两个独立的谱系组成。(1)石藻亚科I，包括以针柄藻门和枝角亚门为代表的分支；(2)石藻亚科II，包括石蕊属、顶管藻门、纤毛藻和扁藻属。盐生绿球藻(Chlorosarcinopsis Halophila)被置于石榴枝中，而小绿球藻是绿藻属(Chlorosarcinopsis)的模式种，属于绿藻科中以基体顺时针方向移位为特征的一个群。对用户定义的树的检查表明，在Ulvophyceae Sensu Mattox和Stewart中包含两个不同谱系的系统发育比该纲的单系支持得更好。我们的结果与van den Hoek等人对Ulvophyceae类的重新定义是一致的。(1995：藻类。生理学导论。剑桥大学出版社)。新属Desmoloris Shin Watanabe，Kuroda&Maiwa Gen.11月是为了适应盐生隐翅虫。
Abstract Electron microscopical observations of the gametes of Helicodictyon planctonicum and the zoospores of Chlorosarcinopsis halophila revealed that the basal bodies are offset in a counterclockwise orientation and are associated with a cruciate flagellar rootlet system; the rhizoplast extends along the d-rootlet. In H. planctonicum, the gametes are covered by scales of indefinite shape, two parallel striated bands connect the posterior flanks of each basal body, probasal bodies are present, and a terminal cap is associated with one microtubular triplet. In C. halophila, the zoospores are naked, the anterior flanks of the basal bodies are linked by a rectangular connecting plate in the region of overlap between the basal bodies, and the proximal end of each basal body is broadly covered by a terminal cap. Molecular phylogenetic analyses were performed using 18S rDNA sequence data for 43 taxa, including new sequences for Chlorosarcinopsis minor, Urospora penicilliformis and Acrosiphonia duriuscula var. tenuis, in addition to H. planctonicum and C. halophila. According to the molecular data, the Ulvophyceae sensu Mattox and Stewart comprises two separate lineages, viz. (1) Ulvophyceae I, including clades represented by Acetabularia and Cladophora; and (2) Ulvophyceae II, including clades of Ulva, Acrosiphonia, Ulothrix and H. planctonicum. Chlorosarcinopsis halophila is placed in the Ulva clade, whereas C. minor, the type species of Chlorosarcinopsis, belongs to a group within the Chlorophyceae characterized by clockwise displacement of the basal bodies. Examination of user-defined trees showed that phylogenies containing two distinct lineages within the Ulvophyceae sensu Mattox and Stewart are better supported than the monophyly of the class. Our results are consistent with the redefinition of the class Ulvophyceae proposed by van den Hoek et al. (1995: Algae. An introduction to phycology. Cambridge University Press). A new genus Desmochloris Shin Watanabe, Kuroda & Maiwa gen. nov. is proposed to accommodate C. halophila.