GROWING GOURMET - Anto2ni.it

8 THE ROLE OF MUSHROOMS IN NATURE
years, the new trees are dug up and replanted
into new environments. This method has had
the longest tradition of success in Europe.
Another approach, modestly successful, is
to dip the exposed roots of seedlings into water
enriched with the spore mass of a
mycorrhizal candidate. First, mushrooms are
gathered from the wild and soaked in water.
Thousands of spores are washed off of the
gills resulting in an enriched broth of inoculum.
A spore-mass slurry coming from several
mature mushrooms and diluted into a 5-gallon
bucket can inoculate a hundred or more
seedlings. The concept is wonderfully simple.
Unfortunately, success is not guaranteed.
Broadcasting spore mass onto the root
zones of likely candidates is another avenue
that costs little in time and effort. Habitats
should be selected on the basis of their parallels
in nature. For instance, Chanterelles can
be found in oak forests of the midwest and in
Douglas fir forests of the west. Casting spore
mass of Chanterelles into forests similar to
those where Chanterelles proliferate is obviously
the best choice. Although the success
rate is not high, the rewards are well worth
the minimum effort involved. Bear in mind
that tree roots confirmed to be mycorrhized
with a gourmet mushroom will not necessarily
result in harvestable mushrooms. Fungi
and their host trees may have long associations
without the appearance of edible
fruitbodies. (For more information, consult
Fox (1983)).
On sterilized media, most mycorrhizal
mushrooms grow slowly, compared to the
saprophytic mushrooms. Their long evolved
dependence on root by-products and complex
soils makes media preparation inherently
more complicated. Some mycorrhizal species,
like Pisolithus tinctorius, a puffball
favoring pines, grow quite readily on sterilized
media. A major industry has evolved
providing foresters with seedlings inoculated
with this fungus. Myconhized seedlings are
healthier and grow faster than nonmycorrhized
ones. Unfortunately, the
gourmet mycorrhizal mushroom species do
not fall into the readily cultured species category.
The famous Matsutake (Tricholorna
magnivelare) may take weeks before its mycelium
fully colonizes the medium on a single
petri dish! Unfortunately, this rate of growth is
the rule rather than the exception with the majority
of gourmet mycorrhizal species.
Chanterelles are one of the most popularly
collected wild mushrooms. In the Pacific
Northwest of North America the harvesting
of Chanterelles has become a controversial,
multi-million dollar business. Like
Matsutake, Chanterelles (Cant ha rellus
cibarius) also form mycorrhizal associations
with trees. Additionally, they demonstrate a
unique interdependence on soil yeasts. This
type of mycorrhizal relationship makes tissue
culture most difficult. At least three organisms
must be cultured simultaneously: the
host tree, the mushroom, and soil yeasts. A
red soil yeast, Rhodotorula glutinis, is crucial
in stimulating spore germination. The Chanterelle
life cycle may have more dimensions
of biological complexity. Currently, no one
has grown Chanterelles to the fruitbody stage
under laboratory conditions. Not only do
other microorganisms play essential roles,
the timing of their introduction appears critical
to success in the mycorrhizal theater.
Senescence occurs with both saprophytic
and myconhizal mushroom species. Often
the first sign of senescence is not the inability
of mycelium to grow vegetatively, but the
loss of the formation of the sexually repro-
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