Systematic reappraisal of species in Phoma section Paraphoma, Pyrenochaeta and Pleurophoma

Abstract

Sequence data from the 18S nrDNA (SSU) and 28S nrDNA (LSU) regions of isolates of Phoma section Paraphoma were compared with those of representative isolates of the morphologically similar anamorph genera Pleurophoma and Pyrenochaeta and of the type species of Phoma sections Phoma, Pilosa and Plenodomus. Phoma section Paraphoma was found to be highly polyphyletic within the Pleosporales and only distantly related to Phoma section Phoma. The genus Paraphoma, which is based on Paraphoma radicina, is reintroduced in the Phaeosphaeriaceae with two additional taxa. The new genera Setophoma and Neosetophoma, type species Setophoma terrestris comb. nov. and Neosetophoma samarorum comb. nov., are introduced and represent species that are closely related to Paraphoma but differ based on morphological characters and molecular phylogeny. Phoma coonsii is transferred to genus Chaetosphaeronema that also belongs to the Phaeosphaeriaceae. Pyrenochaetopsis gen. nov. is introduced to accommodate the type species Pyrenochaetopsis leptospora comb. nov., as well as several other species formerly accommodated in Phoma and Pyrenochaeta. Pyrenochaetopsis is closely related to Pyrenochaeta and classified in the Cucurbitariaceae. Pleurophoma cava is transferred to genus Pyrenochaeta. The new genera elucidate the confusing taxonomy of species in genera Phoma, Pyrenochaeta and Pleurophoma and recognize monophyletic genera with distinct teleomorph affinities.