Reevaluating Cryphonectriaceae and allied families in Diaporthales

The Diaporthales (Sordariomycetes) includes many important families of plant pathogenic fungi, such as the notorious Cryphonectriaceae. The aim of the present study was to reevaluate this family, along with other families in Diaporthales. Based on phylogenetic analyses using combined sequence data of the internal transcribed spacer (ITS) region, large subunit of the nrDNA (28S), and the translation elongation factor 1-alpha (<i>tef1-α</i>) and DNA-directed RNA polymerase II second largest subunit (<i>rpb2</i>) genes, Cryphonectriaceae is separated into two subclades, comprising 21 genera and 55 species. Foliocryphiaceae, fam. nov., is morphologically and phylogenetically its closest relative but is distinct due to its phylogeny and dimorphic conidia. Mastigosporellaceae, fam. nov., is distinguished from other families in Diaporthales by owning apical conidial appendages. <i>Neocryphonectria</i>, gen. nov., within the family Foliocryphiaceae, with two species associated with <i>Carpinus</i> canker in China, is characterized by fusoid, aseptate macroconidia. Additionally, two new combinations are proposed, namely, <i>Cryphonectria citrine</i>, based on <i>Chromendothia citrine</i>, and <i>Cytospora viridistroma</i>, based on <i>Endothia viridistoma</i>. Based on results obtained in this study, 31 families are accepted into Diaporthales.

间座壳目（Diaporthales）隶属于粪壳菌纲（Sordariomycetes），包含诸多重要的植物病原真菌类群科，其中以臭名昭著的隐球壳科（Cryphonectriaceae）为典型代表。本研究旨在重新评估该科以及间座壳目内的其余类群科。本研究结合内部转录间隔区（internal transcribed spacer, ITS）、核核糖体DNA大亚基（large subunit of the nrDNA, 28S）、翻译延伸因子1-α（translation elongation factor 1-α, tef1-α）以及DNA指导的RNA聚合酶II第二大亚基（DNA-directed RNA polymerase II second largest subunit, rpb2）的序列数据开展系统发育分析，结果显示隐球壳科被划分为两个演化支，共计包含21个属与55个物种。叶生隐球壳科（Foliocryphiaceae, fam. nov.，新科）在形态学与系统发育层面与隐球壳科亲缘关系最近，但凭借其独特的系统发育位置以及双型分生孢子，二者得以明确区分。鞭孢壳科（Mastigosporellaceae, fam. nov.，新科）则通过其顶生分生孢子附属物这一特征，与间座壳目内的其他类群科相区分。隶属于叶生隐球壳科的新属新隐球壳属（Neocryphonectria, gen. nov.）包含2个与中国鹅耳枥属（Carpinus）溃疡病相关的物种，该属的典型特征为纺锤形、无隔的大型分生孢子。此外，本研究还提出2个新组合分类：一是由Chromendothia citrine组合而来的柠檬色隐球壳（Cryphonectria citrine），二是由Endothia viridistoma组合而来的绿座壳囊孢（Cytospora viridistroma）。基于本研究的分析结果，间座壳目目前共认可包含31个科。