1 Introduction

Cultivation of Edible Ectomycorrhizal Fungiby in Vitro Mycorrhizal Synthesis 261
Fig. 3. Cross section of a mycorrhiza
of T. borchii on T. platyphyllos
under the light microscope.
Bar 10 µm. (Photograph courtesy
of Paola Bonfante)
paper sandwich techniques (Chilvers et al. 1986), only the beginning of
intercellular penetration is achieved and a well-differentiated mantle is not
formed (Menotta et al., unpubl. data).
TheinvitroformationofmycorrhizasofC. cibarius was obtained by
Danell (1994) using a culture unit system (CUS) where 10 ml of the 5-l
nutrient solution (Ingestad mineral solution) supplemented with glucose
was replaced every 90 min. The C02 concentration in the culture vessel was
also raised to 0.2%. This system led to the formation of mycorrhizas after
8 weeks, and they were fully developed after 10–12 weeks. Moore et al.
(1989) obtained mycorrhizas in 4–5 months in Erlenmeyer flasks, but these
were not fully developed.
Recently, a root organ culture system using transformed roots of Cistus
incanus L. has been used to obtain mycorrhizal association with Tuber
melanosporum mycelia (Roth-Bejerano et al. 2001; Wenkart et al. 2001;
Coughlan and Piché 2004, see Chap. 13) and with T. borchii (Bonfante, pers.
comm.).
3
In Vitro Results to Date
Most of the in vitro mycorrhization techniques applied to edible mushrooms
have been developed to obtain mycorrhizal plantlets, which are then
planted to produce fruiting bodies. Plantlets colonized with Cantharellus
have produced fruiting bodies in the greenhouse (Danell and Camacho
1997). In New Zealand, the first Pinus radiata D. Don plantlets colonized
with L. deliciosus mycelia in pure culture produced commercially viable
fruiting bodies less than 2 years after planting (Wang et al. 2002). Although
plants colonized with porcini and T. matsutake have been obtained, these
have yet to lead to commercial production (Hall et al. 2003b).