Resolving the phylogenetic and taxonomic status of dark-spored teleomorph genera in the Botryosphaeriaceae

Abstract

Species in the Botryosphaeriaceae are common plant pathogens and saprobes found on a variety of mainly woody hosts. Teleomorphs typically have hyaline, aseptate ascospores. However, some have been reported with brown ascospores and their taxonomic status is uncertain. A multi-gene approach (SSU, ITS, LSU, EF1-α and β-tubulin) was used to resolve the correct phylogenetic position of the dark-spored 'Botryosphaeria' teleomorphs and related asexual species. Neodeightonia and Phaeobotryon are reinstated for species with brown ascospores that are either 1-septate (Neodeightonia) or 2-septate (Phaeobotryon). Phaeobotryosphaeria is reinstated for species with brown, aseptate ascospores that bear an apiculus at either end. The status of Sphaeropsis is clarified and shown to be the anamorph of Phaeobotryosphaeria. Two new genera, namely Barriopsis for species having brown, aseptate ascospores without apiculi and Spencermartinsia for species having brown, 1-septate ascospores with an apiculus at either end are introduced. Species of Dothiorella have brown, 1-septate ascospores and differ from Spencermartinsia in the absence of apiculi. These six genera can also be distinguished from one another based on morphological characters of their anamorphs. Although previously placed in the Botryosphaeriaceae, Dothidotthia, was shown to belong in the Pleosporales, and the new family Dothidotthiaceae is introduced to accommodate it.