An integrative re-evaluation of the Fusarium sambucinum species complex

The species-rich Fusarium sambucinum species complex (FSAMSC; Fusarium, Nectriaceae, Hypocreales) is well-known for including devastating plant pathogens and toxigenic species. However, this group of grass-loving fungi also accommodates soil saprobes, endophytes, mycoparasites and rare opportunistic pathogens of humans and other animals. Recent publications have highlighted the vast phylogenetic and biochemical diversity of the FSAMSC, although a large number of taxa in FSAMSC have not been systematically described and still lack Latin binomials. In this study we established the phylogenetic breadth of the FSAMSC using an integrative approach including morphological, multilocus phylogenetic, and coalescence analyses based on five gene regions (calmodulin, RNA polymerase II largest and second largest subunits, translation elongation factor 1-α, and β-tubulin). Results obtained support the recognition of 75 taxa in FSAMSC, including all the currently known species segregates of the Fusarium head-blight pathogen F. graminearum s. lat. Thirty novel species are formally described and illustrated, while four phylogenetic species remain undescribed. An epitype is proposed for the generic type of Fusarium, F. sambucinum, from recently collected material identified by means of morphology, phylogenetics and mating experiments, fixing the phylogenetic application of the name. Additional notes are included on the typification of Fusisporium cerealis (syn. Fusarium cerealis).