CBS-KNAW Fungal Biodiversity Centre, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands;
Persoonia. 2011 Jun;26:57-69. doi: 10.3767/003158511X571841. Epub 2011 Apr 5.
The Mycosphaerella complex is both poly- and paraphyletic, containing several different families and genera. The genus Mycosphaerella is restricted to species with Ramularia anamorphs, while Septoria is restricted to taxa that cluster with the type species of Septoria, S. cytisi, being closely related to Cercospora in the Mycosphaerellaceae. Species that occur on graminicolous hosts represent an as yet undescribed genus, for which the name Zymoseptoria is proposed. Based on the 28S nrDNA phylogeny derived in this study, Zymoseptoria is shown to cluster apart from Septoria. Morphologically species of Zymoseptoria can also be distinguished by their yeast-like growth in culture, and the formation of different conidial types that are absent in Septoria s.str. Other than the well-known pathogens such as Z. tritici, the causal agent of septoria tritici blotch on wheat, and Z. passerinii, the causal agent of septoria speckled leaf blotch of barley, both for which epitypes are designated, two leaf blotch pathogens are also described on graminicolous hosts from Iran. Zymoseptoria brevis sp. nov. is described from Phalaris minor, and Z. halophila comb. nov. from leaves of Hordeum glaucum. Further collections are now required to elucidate the relative importance, host range and distribution of these species.
球腔菌复合体是多系和并系的，包含几个不同的科和属。球腔菌属仅限于具有轮枝孢属无性型的物种，而壳二孢属仅限于与壳二孢属模式种聚类的分类单元，与球腔菌科中的黑星孢属密切相关。发生在禾本科寄主上的物种代表了一个尚未描述的属，为此提出了枝孢壳二孢属。基于本研究中获得的 28S nrDNA 系统发育，枝孢壳二孢属与壳二孢属聚类分开。在形态上，枝孢壳二孢属的物种也可以通过其在培养中类似酵母的生长和形成不同的分生孢子类型来区分，这些类型在壳二孢属中不存在。除了众所周知的病原体，如小麦叶枯病的病原体 Z. tritici 和大麦条斑叶枯病的病原体 Z. passerinii 外，还在伊朗的禾本科寄主上描述了两种叶斑病病原体。短梗枝孢属新种描述于雀麦，盐生枝孢属新组合描述于大麦叶片。现在需要进一步收集以阐明这些物种的相对重要性、寄主范围和分布。
