Graphiola fimbriata: the first species of Graphiolaceae (Exobasidiales, Basidiomycota) described only based on its yeast stage

Abstract

The systematic position of three yeast strains isolated from a plant cell culture, a piece of termite nest, or as a foliar endophyte of Coffea arabica, respectively, is evaluated using morphological, physiological, and phylogenetical characteristics. In culture, all three isolates produced white, pale orange to pink colored colonies of cylindrical cells with monopolar budding and pseudohyphae. Standard phenotypic, biochemical, physiological characterization, and phylogenetic analyses of the combined 26S rRNA gene (D1/D2 domains) and ITS region sequences showed the conspecificity of these isolates and suggest their placement within the Exobasidiales (Ustilaginomycotina) as a sister lineage of the sampled and sequenced Graphiola species. Here, we describe this species as Graphiola fimbriata sp. nov. MycoBank MB 825077 (holotype: PC1T; ex-type cultures: IBRC-M 30158T = CBS 13945T = DSM 104832T). This is the first species described in the genus Graphiola for which only the asexual, saprobic developmental phase is known. The description of the genus Graphiola is therefore emended to allow species known only from a saprobic state.