Verrucoconiothyrium ambiguum sp. nov., a novel species isolated from sea water, and affiliation of the genus Verrucoconiothyrium to the family Didymellaceae.

The genus Verrucoconiothyrium was erected to accommodate Coniothyrium-like species with verruculose conidia. So far, it includes only four species, which have been found in association with plants, and very little is known about their distribution and host preferences. In this study, a Coniothyrium-like fungus isolated from sea water from the north of Portugal was characterised. Phylogenetic analysis, based on sequence data of the internal transcribed spacer and beta-tubulin loci, placed this fungus within the genus Verrucoconiothyrium but clearly distinct from the other known species. A novel species Verrucoconiothyrium ambiguumsp. nov. is described and illustrated. The taxonomic affiliation of the genus Verrucoconiothyrium at the family level was addressed through individual and combined gene genealogies. Our results show that the genus Verrucoconiothyrium is a member of the family Didymellaceae.