A molecular phylogeny of the flagellated fungi (Chytridiomycota) and description of a new phylum (Blastocladiomycota)
A molecular phylogeny of the flagellated fungi (Chytridiomycota) and description of a new phylum (Blastocladiomycota)
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DOI：
10.3852/mycologia.98.6.860
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发表时间：
2006-11-01
期刊：
影响因子：
2.8
通讯作者：
Vilgalys, Rytas
中科院分区：
文献类型：
--
作者：
James, Timothy Y.;Letcher, Peter M.;Vilgalys, Rytas
壶菌门（壶菌）是唯一一门真正的真菌繁殖活动孢子（游动孢子）。壶菌根据其生境、游动孢子特征和生活史可分为五个目。本文利用核糖体DNA序列对壶菌的生殖发育进行了研究。RNA操纵子（18S+5.8S+28S亚基）。令我们惊讶的是，形态上减少的寄生虫Olpidium和Rozella在真菌树上包含两个全新的、独立的谱系。接合菌门（Zygomycota）中的芸苔类Olpidium brassicae类群和Rozella spp.是真菌界最早分化的分支。壶菌门不是单系的，壶菌有四个主要的谱系：Rozella spp.，Olpidium brassicae，Blastocladiales和一个“核心壶菌分支”，包含其余的目和科以及大多数鞭毛真菌。在核心壶菌群11个亚支可以确定，每个相关以及游动孢子超微结构或形态。我们提供了每个分支和它的形态界限的概要。Blastocladiales似乎是大多数无鞭毛真菌的姐妹分类单元。根据分子系统发育和超微结构特征，该目被提升为一门，芽枝菌门。
Chytridiomycota (chytrids) is the only phylum of true Fungi that reproduces with motile spores (zoospores). Chytrids currently are classified into five orders based on habitat, zoospore characters and life cycles. In this paper we estimate the phylogeny of the chytrids with DNA sequences from the ribosomal. RNA operon (18S+5.8S+28S subunits). To our surprise the morphologically reduced parasites Olpidium and Rozella comprise two entirely new, and separate, lineages on the fungal tree. Olpidium brassicae groups among the Zygomycota, and Rozella spp. are the earliest branch to diverge in the fungal kingdom. The phylogeny also suggests that Chytridiomycota is not monophyletic and there are four major lineages of chytrids: Rozella spp., Olpidium brassicae, the Blastocladiales and a "core chytrid clade" containing the remaining orders and families and the majority of flagellated fungi. Within the core chytrid group 11 subclades can be identified, each of which correlates well with zoospore ultrastructure or morphology. We provide a synopsis of each clade and its morphological circumscription. The Blastocladiales appears to be the sister taxon of most nonflagellated fungi. Based on molecular phylogenetic and ultrastructural characters this order is elevated to a phylum, the Blastocladiomycota.