Seven Methods for Storing Edible Mushroom Spawn and Points to Note When Introducing Spawn

Edible mushrooms are rich in nutritional value, require little input for production, and offer high economic returns. In recent years, a wave of edible mushroom production has risen in rural areas. During production, edible mushroom mycelium grows quickly and is prone to aging. Rural conditions are limited, making spawn preservation even more difficult. The following seven simple and easy-to-implement spawn preservation methods are introduced for the reference of the broad farming community:

I. Distilled water method, suitable for the spawn of oyster mushroom, enoki mushroom, and shiitake.

1. To preserve oyster mushroom and enoki mushroom spawn, first move the test-tube spawn that is eight-tenths mature and awaiting preservation into an inoculation box and sterilize it, then use a syringe to inject distilled water through the test-tube plug until the entire surface of the culture medium is submerged, up to 2 cm from the tube mouth. Seal the tube mouth with mineral wax, and place it upright in a cool, shaded place at room temperature; it can be preserved for 1 to 1.5 years.

2. To preserve shiitake and wood ear mushroom spawn, use 150 mm x 15 mm finger-shaped tubes to place solid or semi-solid test-tube spawn cultivated to seven-tenths maturity, under sterile operation in an inoculation box, into 25 mm x 200 mm large test tubes, inject distilled water into the large test tubes up to 1 cm from the tube mouth, wrap the opening with a rubber stopper, and reinforce and seal it with mineral wax, then place it in a cool, shaded place. Wood ear mushroom can be preserved for 7 to 8 months, and shiitake for 9 to 12 months.

This method can also preserve other spawn types at natural temperatures.

II. Urea temporary storage method: place bagged urea in a light-proof, dry, well-ventilated place, bury the main body of the test-tube spawn in the urea granules with the tube mouth exposed outside; spawn vigor can be preserved for as long as 30 days. This method can be carried out under a constant low-temperature environment.

III. Liquid paraffin preservation method: select chemical liquid paraffin, sterilize it under high pressure, then place it in a 40°C constant-temperature incubator for several hours or in a desiccator for several days, and use a sterile pipette or syringe to draw up the liquid paraffin and inject it into the spawn test tube. The injection amount should be about 1 cm above the tip of the slant, and the tube mouth should be plugged with a cotton plug and sealed well with paraffin. Preserved upright in a clean, dry, cool, low-temperature place, it can be kept for 5 years.

IV. Wheat bran preservation method: take a certain amount of wheat bran, add water or nutrient solution, and mix well for later use. Put the wet wheat bran into test tubes, sterilize under high pressure, then mix in the spawn, and culture at a suitable temperature. After the mycelium has developed well, place the test tubes at room temperature to dry. Then preserve in a dry place below 20°C; it can be kept for 3 to 5 years.

V. Physiological saline preservation method: inoculate the spawn into potato culture solution, with each 250 ml Erlenmeyer flask holding 60 ml of culture solution; culture with shaking or shake 5 to 10 times daily for 5 to 7 days, then draw the formed mycelial pellets into test tubes containing 5 ml of sterile physiological saline, transferring about 4 to 5 mycelial pellets per tube, plug with cotton plugs, and seal the tube mouths with wax. It can be preserved at low temperature for 1 year.

VI. Wheat grain preservation method: take high-quality wheat, wash it, soak it in 20°C water for 5 hours, let it dry slightly, and then load it into tubes. The loading amount should preferably be 1/4 to 1/3 of the tube length. After sterilizing the test tubes filled with wheat grains, shake them apart while hot, inoculate the mycelium after cooling, and culture at a suitable temperature until sparse mycelium appears on most wheat grains, then terminate cultivation. The spawn can be placed in a dry place below 25°C and preserved for 1 to 2 years.

VII. Refrigerator preservation method: place well-grown test-tube spawn in a refrigerator. Placed in the fresh-keeping compartment, it can be stored for 7 months. The spawn will not degenerate.

The above methods are all applicable to test-tube spawn.