根虫瘟霉和相关种的分类地位研究及其ITS核苷酸序列分析

Taxonomic position of Zoophthora radicans and its related species and analysis of nrDNA ITS of the isolates

根虫瘟霉是最常见的一种虫霉,寄主广泛,世界广布。目前有学者认为该种是个复合种。本研究对世界不同地区和不同寄主的根虫瘟霉及其近缘类群总计19个菌株,进行3个靶位点(ITS、LSU rDNA、RPB2)的分子系统发育学分析。结果显示,根虫瘟霉ITS长度较为保守性,介于1321-1324bp之间,而所研究的虫霉亚门的其他类群的长度范围较大,为556-1654bp。本研究确认根虫瘟霉是单系种,同时西虫瘟霉、矛孢虫瘟霉和英吉利虫瘟霉具有明确种的分类地位。鬼笔状虫瘟霉种应该被视为西虫瘟霉的异名。

Zoophthora radicans with wide host range and global distribution is one of the most ubiquitous species of entomophthoroid fungi.To explicate the taxonomic position of Z.radicans and its related species,comparison and phylogenetic analyses of sequence data of three target loci,nuclear 28S rDNA,ITS region and the protein-coding RPB2,from 15 Z.radicans isolates and four other Zoophthora species were performed.Analysis result showed that the length of entire ITS in Z.radicans ranging 1321-1324bp is conservative,however,the ITS length in other entomophthoroid species ranging 556-1654bp is diverse.Phylogenetic tree confirms that Z.radicans is monophyletic,and the species status of Z.occidentalis,Z.anglica and Z.lanceolata is explicit.Z.phalloides may be regarded as a synonym of Z.occidentalis.