Bionectriaceae: a poorly known family of hypocrealean fungi with major commercial potential

The ascomycete family Bionectriaceae (Hypocreales) contains cosmopolitan species distributed throughout a broad range of environments, mainly occurring in terrestrial and freshwater ecosystems, with a less frequent occurrence in marine habitats. Members of the family are commonly used in industrial, pharmaceutical, and commercial applications. Applications utilise biodegraders and biocontrol agents, while certain taxa serve as a rich source of bioactive secondary metabolites. In recent years, several studies have proposed new taxonomic concepts within Bionectriaceae based on multi-gene phylogenetic inference. However, the status of several genera remains controversial or unclear, and many need to be re-collected and subjected to molecular analysis. The present study aims to improve our understanding of Bionectriaceae by re-examining CBS culture collection strains preliminarily identified as taxa within this family. Morphological and molecular phylogenetic analyses are based on alignments of the nuclear ribosomal subunits consisting of the internal transcribed spacer regions and intervening 5.8S nrDNA (ITS), as well as partial sequences for the 28S large subunit (LSU) nrDNA. Additional regions within protein-encoding genes were used, including the DNA-directed RNA polymerase II second largest subunit (RPB2), and translation elongation factor 1-alpha (TEF1) regions. The sequences generated were used to reconstruct a phylogenetic backbone of the family Bionectriaceae, and to delineate lineages and generic boundaries within it. Based on these results, seven new genera, 35 new species, and nine new combinations are proposed. A robustly supported phylogenetic framework is provided for Bionectriaceae, resolving 352 species and 50 well-supported genera. This study provides a solid foundation for more in-depth future studies on taxa in the family.