CULTIVATION OF EDIBLE ECTOMYCORRHIZAL MUSHROOMS IN JAPAN

Japan is a mycophilic country where hundreds of species of wild edible fungi are consumed, including ectomycorrhizal species. Worldwide, the cultivation of ectomycorrhizal edible fungi represents a challenge of great economic, ecological and cultural relevance. This paper presents a review of the advances in the cultivation of edible ectomycorrhizal fungi developed in Japan. The greatest achievements have been carried out in some species of shimeji (Lyophyllum spp.), matsutake (Tricholoma matsutake) and the hypogeous fungus called shoro (Rhizopogon roseolus). In addition, some advances have been made in species of the genera Astraeus, Cantharellus, Sarcodon, Suillus and Tuber. Some of these latter species have received only interest in Japan, because they have culinary value exclusively in Eastern Asia. The cultivation of L. shimeji, a mushroom highly valued in the Japanese culture, has been achieved in the absence of host plants. The cultivation of matsutake, an iconic fungus of Japanese culture, has received great attention due to its dramatic decline of natural production in Pinus densiflora forests from the 1940s to the present, in Japan. The studies have been developed in laboratory, greenhouse and field conditions and have focused on the application of forest management techniques, the establishment of mycorrhizal tree plantations and the inoculation of trees with mycelium and spores. The key to the successful cultivation of these fungi requires a better understanding of the physiological, ecological, biochemical and genetic mechanisms involved in the mycorrhizal symbiotic relationship between trees and fungi, as well as in the understanding of the biotic and abiotic factors involved in the formation of basidiomata in field conditions. The methodological advances in these areas may allow the successful establishment of commercial plantations inoculated with fungi native to Japan. One of the main challenges is the enormous native diversity of species of ectomycorrhizal fungi that exist naturally in Japan, which represents a competitive factor for the success of plantations aimed to produce specific fungal species. However, given the great interest that exists in the country, this area of research looks very promising in the following decades.