Chemotaxonomic and molecular phylogenetic studies of selected Hypoxylon species from the Neotropics

Abstract

Members of the genus Hypoxylon (Ascomycota) are pleomorphic fungi mostly forming conspicuous teleomorphs, consisting of perithecia embedded into stromal tissue, and their morphology has traditionally served for species delineation. However, analysis in tandem with other phenotypic characters, such as chemical and genetic traits, proved to be a more stable predictor of interspecies and intergeneric relationships. During 2014 and 2015, a set of species identified as Hypoxylon were described from the Neotropics, exclusively relying on morphological traits. The secondary metabolite profiles of their stromata were analysed by HPLC/DAD-ESI-MS, corroborating their classification within Xylariales. Additionally, molecular data for ex-type strains of H. dussii and H. sofaiense were incorporated into an inferred molecular phylogeny of the Hypoxylaceae and allies. Furthermore, a freshly collected specimen from North Carolina was selected as epitype of Sphaeria perforata Schweinitz (syn. Hypoxylon perforatum), as its morphological/chemotaxonomic characters matched those of the holotype. Our findings demonstrate that the secondary metabolism of Hypoxylon closely correlates with both morphological features and molecular data, serving as a complement for species identification.