Biological characteristics of teleomorph and optimized in vitro fruiting conditions of the Hoelen medicinal mushroom, Wolfiporia extensa (Higher Basidiomycetes).

Wolfiporia extensa is a basidiomycetous brown rot fungus and is of well-known medicinal import in China, Japan, and other Asiatic countries. Fruiting body induction is of major relevance for basic biological research and for their use in industrial applications. Based on the evaluation of the effects of temperature, time in the dark before induction and culture, and wounding treatment on fruiting, this report describes the most efficient protocol for inducing fruiting of W. extensa growing on agar plates. Furthermore, several biological characteristics of teleomorph, such as the locations of hymenium, the configuration of basidiospores and primary mycelia, and events involved in basidiosporogenesis in W. extensa, were analyzed for the first time using fluorescence microscopy. The results showed that the hymenium born on both sides of the wall of the honeycomb-like structure on the surface of fruiting bodies and the hymenophoral trama situated in the middle. Each basidia has 4 binuclear basidiospores, and the primary mycelia are multinucleate without clamp connections. These results broaden our knowledge about this brown rot fungus and promote further studies of the sexual reproduction, fruiting body development, and advancement of breeding program, new topics related to the contents of pharmacologically active substances in W. extensa fruiting bodies.