Towards a backbone tree for Seimatosporium, with S. physocarpi sp. nov

Abstract

The genus Seimatosporium is saprobic or pathogenic on plants, and are 'pestalotioid fungi'. The genus presently belongs in Discosiaceae (Amphisphaeriales) and includes 78 species epithets. In this study, we observed three specimens of Seimatosporium from Russia and they are characterized by morphological and sequence data. We analyzed combined ITS and LSU gene sequence data of 42 species representing the genera Discostroma (7), Sarcostroma (2) and Seimatosporium (32, including the three new strains) with Pseudopestalotiopsis theae as the outgroup taxon. One isolate from dead branches of Physocarpus opulifolius is unique and is introduced as Seimatosporium physocarpi sp. nov., in this paper. It can be distinguished from similar and related species by phenotypic conidial characters and phylogenetic analyses. A specimen from Rosa kalmiussica Chrshan. & Lasebna (often included in Rosa canina sensu lato) is designated as an epitype for S. rosae, the type of the genus. In addition, a collection of S. lichenicola is described, illustrated and compared with other species in the genus.