Yeasts of the now unused asexually typified genus Pseudozyma belong to the smut fungi (Ustilaginales) and are mostly believed to be apathogenic asexual yeasts derived from smut fungi that have lost pathogenicity on plants. However, phylogenetic studies have shown that most Pseudozyma species are phylogenetically close to smut fungi parasitic to plants, suggesting that some of the species might represent adventitious isolations of the yeast morph of otherwise plant pathogenic smut fungi. However, there are some species, such as Moesziomyces aphidis (syn. Pseudozyma aphidis) that are isolated throughout the world and sometimes are also found in clinical samples and do not have a known plant pathogenic sexual morph. In this study, it is revealed by phylogenetic investigations that isolates of the biocontrol agent Moesziomyces aphidis are interspersed with M. bullatus sexual lineages, suggesting conspecificity. This raises doubts regarding the apathogenic nature of asexual morphs previously placed in Pseudozyma, but suggests that there might also be pathogenic sexual morph counterparts for those species known only from asexual morphs. The finding that several additional species currently only known from their yeast morphs are embedded within the genus Moesziomyces, suggests that the yeast morph might play a more dominant role in this genus as compared to other genera of Ustilaginaceae. In addition, phylogenetic reconstructions demonstrated that Moesziomyces bullatus has a narrow host range and that some previously described but not widely used species names should be applied for Moesziomyces on other host genera than Echinochloa.

中文翻译：

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重新审视墨氏酵母的无性和有性变形。


目前未使用的无性典型假酵母属的酵母属于黑粉病真菌（黑粉菌目），并且大多数被认为是源自对植物已失去致病性的黑粉病真菌的非致病性无性酵母。然而，系统发育研究表明，大多数假酵母物种在系统发育上与寄生在植物上的黑粉菌真菌接近，这表明某些物种可能代表其他植物致病性黑粉菌真菌的酵母形态的偶然分离。然而，有一些物种，例如 Moesziomyces aphidis（同义词 Pseudozyma aphidis），在世界各地被分离出来，有时也在临床样本中发现，并且不具有已知的植物致病性有性形态。在这项研究中，通过系统发育研究表明，生物防治剂 Moesziomyces aphidis 的分离株散布于 M. bullatus 有性谱系中，这表明了同源性。这引起了人们对先前置于假酵母中的无性变体的非致病性质的怀疑，但表明对于仅从无性变体已知的那些物种，也可能存在致病性有性变体对应物。研究发现，目前仅通过其酵母变体已知的其他几个物种被嵌入Moesziomyces属中，这表明与黑粉菌科的其他属相比，酵母变体可能在该属中发挥着更重要的作用。此外，系统发育重建表明，Moesziomyces bullatus 的宿主范围较窄，一些先前描述但未广泛使用的物种名称应适用于稗草以外其他宿主属上的 Moesziomyces。