Phylogeny of the genus Arthrobotyrs and allied nematode-trapping fungi based on rDNA sequences
Phylogeny of the genus Arthrobotyrs and allied nematode-trapping fungi based on rDNA sequences
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DOI：
10.2307/3761108
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发表时间：
1997-11-01
期刊：
影响因子：
2.8
通讯作者：
Tzean, SS
中科院分区：
文献类型：
--
作者：
Liou, GY;Tzean, SS
采用聚合酶链反应（PCR）技术，对节孢霉属、指状孢属、杜丁顿氏菌属、Geniculifera属、单孢霉属、线虫属等29种捕食线虫真菌和Orbilia属、单孢霉属、指状孢属、节孢霉属等5种非捕食性近缘真菌的核糖体DNA进行扩增，并利用通用引物进行序列测定。系统发育分析表明，28种捕食线虫的无钳型真菌具有单系性，它们都是从同一个祖先进化而来的。钳形粗纹章鱼（Nematoctonus robustus）具有Hohenbuehelia担子菌有性型，在系统发育上距离较远，其捕食习惯是通过趋同进化获得的。Nonpredacious Arthroboticus，Dactylaria，和Trichothecium物种，尽管有形态相似的产孢细胞和分生孢子，实际上是在一个遗传上遥远的区域的树分组。对ITS 1和ITS 2的分析表明，28株捕食线虫真菌可分为4个分支，每个分支都有独特的捕食装置。本研究中的诱捕真菌rDNA系统发育分析表明，诱捕器官可能反映进化关系，比产孢细胞和分生孢子在属种划分上更有意义。我们建议修改节丛菌属-指状孢属-单顶孢属复合体的界限，以提供一个自然的分类系统。
Ribosomal DNA of 29 nematode-trapping fungi in the genera Arthrobotrys, Dactylella, Duddingtonia, Geniculifera, Monamosporium, Nematoctonus, and 5 nonpredacious, allied fungi in the genera Orbilia, Trichothecium, Dactylaria, and Arthrobotrys was amplified by polymerase chain reaction and sequenced using universal primers. Phylogenetic analysis of 5.8S rDNA using parsimony indicated that 28 clampless nematode-trapping fungi were monophyletic and have evolved from a common ancestor. Clamped Nematoctonus robustus, having a Hohenbuehelia basidiomycetous teleomorph, was phylogenetically distant and the predacious habit was gained through convergent evolution. Nonpredacious Arthrobotrys, Dactylaria, and Trichothecium species, despite having morphologically similar conidiogenous cells and conidia, actually were grouped in a genetically distant region of the tree. Analysis of the more variable internal transcribed spacer, ITS1 and ITS2, revealed that the 28 nematode-trapping fungi were separated into 4 clades, each with a unique trapping device. Phylogenetic analysis of rDNA of trapping fungi in this study indicated that trapping organs may reflect evolutionary relationship, and appear more significant than conidiogenous cells and conidia for genus and species delimitation. We suggest that the circumscription of the Arthrobotrys-Dactyella-Monacrosporium complex be revised to provide a natural classification system.