Epitypification of Fusisporium (Fusarium) solani and its assignment to a common phylogenetic species in the Fusarium solani species complex

Abstract

Fusisporium solani was described as the causal agent of a dry rot of potato in Germany in the mid 19th century. As Fusarium solani, the species became known as a plurivorous plant pathogen, endophyte, decomposer, and opportunistic pathogen of humans and nutritional symbiont of insects. In parallel, it became evident that the morphologically defined species F. solani represents a phylogenetically and biologically complex group of often morphologically cryptic species that has come to be known in part as the F. solani species complex (FSSC), accommodating several formae speciales and mating populations/biological species. The FSSC currently includes more than 60 phylogenetic species. Several of these have been named, but the majority remains unnamed and the identity of F. solani sensu stricto is unclear. To promote further taxonomic developments in the FSSC, lectoand epitypification is proposed for Fusisporium solani. Although no type material for F. solani is known to exist, the species was abundantly illustrated in the protologue. Thus, a relevant illustration provided by von Martius is selected as the lectotype. The epitype selected here originates from a rotting potato collected in a field in Slovenia. This strain causes a dry rot of artificially inoculated potatoes. It groups in the heretofore unnamed phylogenetic species 5, which is nested within clade 3 of the FSSC (FSSC 5). Members of this phylogenetic species have a wide geographic distribution and include soil saprotrophs and plant and opportunistic human pathogens. This typification is consistent with the original description of Fusisporium solani and the concept of F. solani as a widely distributed soil inhabitant and pathogen.