Professor Cobus Visagie represented FABI at the Westerdijk Fungal Biodiversity Institute (Utrecht, the Netherlands) Spring Symposium on "DNA Sequences as Type" on 7–8 April. This two-day event brought together leading mycologists from around the world to consider how DNA sequences could serve as nomenclatural types for fungi. This is a fundamental challenge in modern mycology with a significant proportion of fungi being unculturable and known only from environmental DNA sequences, with no physical specimens available for study. This issue has become increasingly important as environmental sequencing continues to reveal thousands of previously unknown fungal taxa. The gathering in Utrecht provided an opportunity to shape proposals that may have a direct impact on the International Code of Nomenclature for Algae, Fungi, and Plants.

There have been numerous previous unsuccessful attempts to reach consensus on how to deal with DNA sequences as types for fungi, including at the International Mycological Congress (IMC) in Puerto Rico (2018) and recently in Maastricht (2024). The outcomes of the discussions in Utrecht will now help to prepare proposals for voting at IMC13 in South Korea in 2027. Key discussion topics included: i) The naming of environmental sequences (so-called "dark taxa"); ii) Whether DNA sequence data can serve as holotypes;iii) Naming species based solely on DNA characters; and iv) Understanding that a species is more than just its DNA sequence.

At the first of two concurrent workshops at the symposium chaired by Robert Lücking & Urmas Kõljalg, participants discussed the development of a proposal to allow "Short DNA Sequences for the provisional naming of fungi". The other workshop chaired by Marco Thines, Jacob Steenwyk & Maria Chuvochina, focused on "Genome Data as Type". Discussions were fruitful, and working groups of the International Commission on the Taxonomy of Fungi (ICTF) will now develop formal proposals and guidelines together with the Special Purpose Committee appointed by the Nomenclatural Committee of Fungi.

Prof Cobus Visagie of FABI and a member of the ICTF participated in the discussions and presented a talk "From morphology to DNA: Using the modern taxonomy of Eurotiales to explore the potential of DNA sequences as types". During the symposium, he was also awarded the prestigious Johanna Westerdijk Award.