Towards the cultivation of the bay boletus, Imleria badia: Primordia formation, mycorrhizal synthesis and geographic distribution

Aim of study: Here we take the first steps towards the cultivation of the gastronomically appreciated ectomycorrhizal fungus known as the bay boletus, Imleria badia (Fr.) Vizzini (2014). The cultivation of ectomycorrhizal species with their hosts presents a mycoforestry system in which food production and forestry can exist on the same parcel of land. We present results of attempts to synthesize I. badia mycorrhiza alongside an investigation into the distribution and climate tolerance of the species. Area of study: The mycorrhizal-development component of the study takes place in laboratory and greenhouse facilities in Scotland, UK. The second component of biogeographic analysis covers the whole of Europe. Material and methods: Strains of I. badia are sampled from forest sites in Scotland (UK), before being isolated in agar-based media within the laboratory. Mycorrhizal synthesis is attempted using the host tree species Pinus sylvestris L. in greenhouse conditions. Biogeographic analysis is then undertaken using global occurrence records from the Global Biodiversity Information Facility. Main results: One isolated strain displayed the unusual characteristic of forming primordia in pure culture. Mycorrhizal synthesis occurred with the application of basidiospores, mycelia or a combination of both inoculation methods and identification was confirmed with PCR. Biogeographic analysis showed a broad distribution across Europe with some clear regional trends in seasonal fruiting patterns. Research highlights: Successful mycorrhizal synthesis in greenhouse conditions of this gastronomically valued species presents the first step on the road to cultivation. A ready ability to produce primordia suggests high potential and biogeographic analysis allows informed selection of field-trial sites as the next step towards the goal of cultivation.