GROWING GOURMET - Anto2ni.it

Figure 44. Scanning electron micrograpti otmycelium.
vironment, breaking down lignin-cellulose
complexes into simpler compounds. The mushroom
mycelium absorbs these reduced organic
molecules as nutrients directly through its cell
walls. After one mushroom species has run its
course, the partially decomposed substrate becomes
available to secondary and tertiary
saprophytes who reduce it further. Ultimately,
a rich soil is created for the benefit of plants and
other organisms.
As the mycelium expands, a web of cells is
formed, collectively called the mycelial network.
The arrangement of these cells is
designed to optimally capture an ecological
niche. Species differ in the manner by which the
mycelial mat is projected. Initially, Morel
mycelium throws a thinly articulated mycelial
network. (Morel mycelium is the fastest-growing
of any I have seen. ) Once a substantial
territorial domain has been over-run, side
THE MUSHROOM LIFE CYCLE 67
branching of the mycelium occurs, resulting in
a thickening of the mycelial mat.
With the approach of winter, the mycelial
mat retreats to survive in specific sites. At this
time, many mushrooms, both gilled and nongilled,
produce scierotia. Scierotia are a resting
phase in the mushroom life cycle. Scierotia resemble
a hardened tuber, wood-like in texture.
(See Figures 42 and 43. )While in this dormant
state, the mushroom species can survive inclement
weather conditions like drought, fire,
flooding, or other natural catastrophes. In the
spring, the scierotia swell with water and
soften. Directly from the scierotia, mushrooms
emerge. Morels are the best known mushrooms
which arise from sclerotia. (See Figures 359-
360). By the time you find a mature Morel, the
sclerotia from which it came will have disappeared.
Most saprophytic mushrooms produce a thick
mycelial mat after spore germination. These
types of mycelial mats are characterized by
many cross-overs between the hyphae. When
two spores come together and mate, the downstream
mycelium produces bridges between the
cells, called clamp connections. Clamp connections
are especially useful for cultivators who
want to determine whether or not they have
mated mycelium. Mycelium arising from a
single spore lacks clamp connections entirely,
and is incapable of producing fertile mushrooms.
As the mycelial network extends, several byproducts
are produced. Besides heat, carbon
dioxide is being generated in enormous quantities.
One study (Zadrazil, 1976) showed that
nearly 50% of the carbon base in wheat straw
is liberated as gaseous carbon dioxide in the
course of its decomposition by Oyster mushrooms!
10% was converted into dried
mushrooms: 20% was converted to proteins.
Other by-products include a variety of volatile
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