Edible ectomycorrhizal mushrooms: challenges and achievements

There are about 2500 recorded species of edible mushrooms. The most expensive and sought after of these mushrooms belong to the mycorrhizal group and include Tuber melanosporum Vitt. (Perigord black truffle), Tuber magnatum Pico & Vitt. (Italian white truffle), Tricholoma matsutake (Ito & Imai) Sing. (matsutake), Boletus edulis Bull: Fr. sensu lato (porcini) Cantharellus cibarius Fr.: Fr. (chanterelle), and Amanita caesarea (Scop.: Fr.) Pers: Schw. (Caesar's mushroom). The total market for these is measured in billions of US dollars. Over the past 100 years, harvests of many mycorrhizal mushrooms have declined dramatically, which has prompted interest in the development of methods for their cultivation. So far only a few species of truffles have been produced in commercial quantities, although methods have been developed that may see the cultivation of species such as Cantharellus cibarius, Lyophyllum shimeji (Kawam.) Hongo, and Lactarius deliciosus (L.: Fr.) Gray. Despite this, many of the most expensive mycorrhizal mushrooms, including Tuber magnatum Pico & Vitt. and Tricholoma matsutake, have defied cultivation. Our paper will attempt to highlight possible reasons why mycorrhizal mushrooms have proven to be so difficult to grow and how we might better manage mycorrhizal mushroom forests to sustain natural production.