Basidiome formation of an edible wild, putatively ectomycorrhizal fungus, Phlebopus portentosus without host plant

Abstract

Phlebopus portentosus is a popular wild edible ectomycorrhizal fungus in northern Thailand. In general ectomycorrhizal fungi produce basidiomes when associated with a host plant. In this paper mycelium growth and basidiome production of P. portentosus were examined in pure culture both in vitro and in pot-culture experiments. Five mycelial strains of P. portentosus were isolated from basidiomes and used in the experiments. The mycelia grew fastest on sorghum grains supplemented with fungal-host solution. The mycelia produced sclerotia-like structures after 3 wk incubation in darkness at 30 C. All strains of P. portentosus had the ability to form primordia. The primordia were formed under lowered temperature, high humidity and a 12 h photo-period. They developed to mature basidiomes after 8–12 d in in vitro. In the pot-culture primordia were found after 28–35 d incubation in the greenhouse and mature basidiomes released basidiospores within 6–8 d. Basidiospores were germinated on fungal-host medium and formed mycelial colonies. This fungus showed an ability to produce basidiomes even 2 y after the original isolation from tissues. This research provides valuable information concerning the techniques and protocols for the large scale commercial production of P. portentosus basidiomes in the absence of a host plant.

• bolete
• cultivation
• edible mushroom
• pure culture

Acknowledgments

This work was supported by grants from The Royal Golden Jubilee Ph.D. Program ( PHD/0309/2550), Graduate School of Chiang Mai University, and The Higher Education Commission, Thailand, under the National Research University (A1) Program. Eric Danell was supported by the Karljohan Foundation.

We are grateful for the help of Keegan H. Kennedy, Department of Biology, Chiang Mai University, who improved the English.