Cultivation Corner
By Marc-Andrew Donsky
e-mail: mad@amigo.net
Cultivation I
Perhaps this will be the year when you devote a corner
of your garden to growing your own portabelas, criminis,
shitakes, shaggy manes, Lepiotas, oysters, enokitakes. In
this column we will give a basic outline of mushroom
cultivation techniques and try to answer your questions
about cultivation.
Each column will briefly cover a different aspect of
mushroom cultivation:
I. Growth on Agar
II. Growth on Grain
III. Growth on Compost
IV. Pests and Diseases plus culture maintnenance
V. Growth on Logs
I hope cultivation corner will provide stimulus and
help you establish your own cultivation corner. Happy
hunting and growing!
I. Growth on Agar:
The first phase of mushroom cultivation is the isolation
of a pure culture of mycelium. Nutrient agar provides the
medium on which this takes place. The two most commonly
used nutrients agars for mushroom cultivation are Potato
Dextrose (Yeast) Agar (PD(Y)A) and Malt-Extract Agar
(MEA). Potato Dextrose (Yeast) Agar is most often used
for tissue culture and Malt-Extract Agar is usually the
medium of choice for spores.
PD(Y)A should be sterilized for 45 minutes at 15
pounds pressure. MEA should be sterilized for 30 minutes
at 15 pounds pressure. Sterilization of MEA for more than
30 minutes can lead to caramelization of the malt sugars.
Most mushrooms prefer a neutral to slightly acid pH. That
is a pH of 5.5 to 7.0. These two recipes should result in
medium within this pH range without further adjustment.
Petri dishes, baby bottles and baby food jars all make
good containers for agar.
Potato Dextrose (Yeast) Agar (PD(Y)A):
Potato Water 1 liter
Dextrose 10 grams
Nutritional Yeast or Yeast Extract 1-3 grams (optional)
Agar- agar 20 grams Potato water is prepared by boiling a
large, washed but not peeled, thinly sliced potato in
water for one hour. The potato water is strained, brought
to one liter of volume and the other ingredients then
added prior to sterilization. Malt-Extract Agar (MEA)
Malt- extract 15 grams. Agar-agar 20 grams
Water 1 liter Optional: Potassium biphosphate 0.1 gram
and Calcium carbonate 0.1 gram Inoculation of Agar for
Culture Isolation: Mycelia can be gotten from spores or
tissue culture. Tissue cultures may be taken from any
clean portion of the mushroom using a sterilized exacto
knife or surgical blade. Spores may be started form
pieces of gill tissue, spore prints, or direct spore
drops onto to agar made by placing a portion of the
mushroom with the gills toward the agar surface on the
roof (cap, top,) of the petri dish using a touch of
Vaseline.
Commonly used spore isolation techniques
include:
A. Streak Method:
Spores are transferred to one portion of the agar plate
which is then streaked across with an inoculation loop to
another portion of the plate in order to separate
individual spores and make the single colonies available
for isolation.
B. Dilution Method:
Spores are soaked in cooled sterilized distilled water
for several hours. Stir an inoculation loop in the spore
solution and streak the petri dish, or using a sterile
eyedropper put a drop of the spore solution onto the
petri dish and spread. Agar to agar inoculations can be
easily done using sterile technique with an exacto knife,
surgical blade or an inoculating loop.
Once a pure culture of mycelium has been isolated, it
is allowed to take over the agar dish. With mycelium
grown from single spores it will be necessary to
co-incubate two monokarotic cultures in order to generate
the dikaryotic culture needed to yield mushrooms. This
can be done by inoculating two pure spore cultures onto
the same agar plate, or by placing the two cultures into
the same jar of grain. If mycelium has been isolated by
tissue culture of a carpophore, you are now ready for
transfer to grain media.
Advice for
Beginners || About CMS || Colorado
Links || Home
|| Links ||
Member
Activities || Meetings || Mushroom
Fair || Mushroomers
Message Center ||
NAMA
|| Recipes || Spores
Afield || Site Index || Telluride
Mushroom Conf. || Whats
New ||
mycosociety@angelfire.com
©2000
Colorado Mycological Society - All rights reserved
|