ABSTRACT The phylogeny and taxonomy of powdery mildew on Viburnum species is evaluated and discussed. Morphological and phylogenetic analyses revealed two new species and demonstrated that Erysiphe hedwigii and E. viburni should be reduced to synonymy and are referred to herein as E. viburni. The two new species, E. viburniphila and E. pseudoviburni, previously hidden under E. viburni (including E. hedwigii), is described on the basis of European, North American, and East Asian powdery mildew collections on Viburnum edule, V. tinus, V. odoratissimum var. awabuki, and V. sieboldii. The sexual morph of E. viburniphila is similar to that of E. viburni; however, morphological differences exist in their asexual morphs. Analyses of sequences from the internal transcribed spacer (ITS) and 28S genomic regions of Erysiphe species obtained on Viburnum species (and other closely allied Eryisphe species) throughout the world reveled that E. viburniphila and E. pseudoviburni are in two different monophyletic groups that are separate from all other Erysiphe species. Erysiphe hedwigii and E. viburni on Viburnum species have often been recognized as separate species based on morphological differences in the size of their chasmothecia and the number of chasmothecial appendages. Taxonomic conclusions based on these morphological distinctions within these species are unreliable (these characters are rather variable and often have overlapping ranges). The present phylogenetic analyses suggest that E. hedwigii has to be reduced to synonymy with E. viburni. To fix the application of the species names E. hedwigii and E. viburni, epitypes have been designated for these taxa with ex-epitype sequences. Additionally, the Asian species E. miranda is phylogenetically confirmed as a species of its own, described in detail and discussed.

中文翻译：

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荚膜白粉病的系统发育和分类学

摘要 评估和讨论了荚膜白粉病的系统发育和分类学。形态学和系统发育分析揭示了两个新物种，并证明 Erysiphe hedwigii 和 E. viburni 应简化为同义词，在本文中称为 E. viburni。先前隐藏在 E. viburni（包括 E. hedwigii）下的两个新物种 E. viburniphila 和 E.pseudoviburni 是根据欧洲、北美和东亚在 Viburnum edule, V. tinus 上收集的白粉病菌来描述的, V. odoratissimum var. awabuki 和 V. sieboldii。E. viburniphila 的有性形态与 E. viburni 相似；然而，它们的无性变体存在形态差异。对来自世界各地荚蒾种（和其他密切相关的白粉菌种）的内转录间隔区 (ITS) 和 28S 基因组区域的序列进行分析，发现 E. viburniphila 和 E.pseudoviburni 属于两个不同的单系群，它们是与所有其他白粉菌物种分开。Erysiphe hedwigii 和 E. viburni on Viburnum 物种通常被认为是独立的物种，因为它们的 chasmothecia 大小和 chasmothecial 附属物数量的形态差异。基于这些物种内的这些形态差异的分类学结论是不可靠的（这些特征相当多变并且经常有重叠的范围）。目前的系统发育分析表明 E. hedwigii 必须简化为 E. viburni 的同义词。为了解决物种名称 E. hedwigii 和 E. viburni 的应用问题，已为这些具有前表型序列的分类群指定表型。此外，亚洲物种 E. miranda 被系统发育证实为它自己的物种，详细描述和讨论。