A molecular-taxonomic reappraisal of the common but much overlooked basidiomycete truffle genus Hymenogaster

The poorly understood fungal genus Hymenogaster (Agaricales, Basidiomycota) comprises mycorrhizal basidiomycetes that form subterranean truffle-like fruiting bodies in calcareous soils.

While soil metabarcoding is revealing a vast, largely undescribed biodiversity of the genus, scientific progress is hampered by the lack of taxonomic expertise to make sense of the results.

The unclear definition of the genus, the vast disagreements on species identities and numbers, and contradictory cues on the ecological context of the genus do little to ameliorate the situation.

The present project will train a Ph.D. student in modern Hymenogaster taxonomic practise to settle the many lingering questions in the genus: circumscription, species limits and identity, and ecological context.

This will be achieved by field work in the previously unsampled – but Hymenogaster-rich – northern parts of Sweden using trained truffle-sniffing dogs, coupled with recourse to extant herbarium specimens and sequence data.

Metabarcoding and biodiversity informatics data mining in the context of the UNITE database for molecular identification of fungi will be used to pursue the available but unexplored cues to the ecological context of the genus.

Morphological study with ensuing species descriptions and typifications will be undertaken to address the taxonomic shortcomings facing students of the genus. Ample open data, digital media use, and public data integration will be part of the taxonomic training.