Fig. 1.

Formation of a P. betulinus PB01 fruiting body on birch sawdust. a Bag with growing mycelium (20 days after inoculation). b Longitudinal section of the substrate overgrown by mycelium. c Infection of the substrate surface with Trichoderma sp. d 9-day-old pinheads. e 20-day primordia. f Fruiting body inside the bag. g Mature fruiting body. h Bags with growing mycelium. i Bags with mature fruiting bodies. Ml mycelium layer, Fi fungal (Trichoderma) infection, Ph pinheads, Pr primordium, Fb fruiting body