Molecular phylogeny reveals the true colours of Myeloconidaceae (Ascomycota: Ostropales)

Abstract

The lichen-forming fungal family Myeloconidaceae, with the single genus Myeloconis, has been suggested to share affinities with Porinaceae (Lecanoromycetes: Ostropales). We examined its position relative to this family by using molecular data from the mitochondrial small-subunit and nuclear large-subunit rDNA. Our results revealed that Myeloconis forms a monophyletic group nested within Porinaceae, closely related to Porina farinosa. Neither Porina s.str. nor Clathroporina sensu Harris form monophyletic groups; instead, two strongly supported clades were recovered, which differ in ascospore septation (septate v. muriform), with the clade producing muriform ascospores including Myeloconis. We therefore reduce Myeloconidaceae to synonymy with Porinaceae; however, because generic delimitations within Porinaceae remain unclear, we retain Myeloconis as a separate genus within the family. The species concept currently used in the genus, based largely on secondary metabolites and ascospore measurements, is supported by the phylogeny.