Epityfication of Perisporiopsis struthanthi and Perisporiopsis lantanae, and the taxonomic implications for Perisporiopsidaceae, Perisporiopsis and Setophoma

Abstract

Abstract Perisporiopsidaceae includes species with superficial ascomata seated on a subiculum, and ellipsoidal oblong, one or more septate, hyaline ascospores. Taxonomy of species in this family has been based, mainly, on morphological characters and host/substrate associations. There is limited information about the taxonomic placement of Perisporiopsidaceae within the Dothideomycetes. Here, an assessment of the phylogenetic position of the Perisporiopsidaceae was conducted based on a multilocus phylogenetic analysis of sequence data obtained from fresh material of the type species of Periosporiopsis – Perisporiopsis struthanthi. An epitype is designated here. In addition, novel specimens and pure cultures of Perisporiopsis lantanae were also obtained, inclusive from the type locality and subjected to molecular analysis. Additionally the status of Perisporiopsis lateritia was investigated. Perisporiopsis struthanthi and P. lantanae were found to belong to a clade within the Phaeosphaeriaceae. Perisporiopsis struthanthi grouped with Setophoma spp. and P. lantanae isolates formed a separate clade within Phaeosphaeriaceae. There was, nevertheless, no morphology-based indication of a connection between Perisporiopsis and Setophoma. The members of Setophoma spp. that are closer to Perisporiopsis struthanthi (Setophoma sacchari, S. pseudosacchari, S. vernoniae, S. chromolaenae, S. antiqua, and S. endophytica) are combined herein into Perisporiopsis as, P. antiqua, P. chromolaenae, P. endophytica, P. pseudosacchari, P. sacchari, and P. vernoniae,). Additionally, Setophoma is splited into three genera: Setophoma stricto sensus (including the type species Setophoma terrestris, S. brachypodii, and S. poaceicola), Pseudosetophoma (type Pseudosetophoma yunnanensis, and with P. yingyisheniae), and Troglophoma (type Troglophoma caverna, and with T. longinqua). Perisporiopsis lateritia grouped in the family Pyrenochaetopsidaceae, Perisporiopsidaceae is merged into Phaeosphaeriaceae, a family having nomenclatural priority over Perisporiopsidaceae. A new genus and combination are proposed to accommodate P. lantanae, namely Sputnikia and Sputnikia lantanae whereas P. lateritia is combined to Pyrenochaetopsis lateritia. Other species and genera in Perisporiopsidaceae should be regarded as Incertae sedis, until specimens are recollected and epitypes designated, or DNA sequences obtained from the type specimens and a molecular phylogenetic study clarifies their taxonomic position.