Methods for Preserving Edible Fungi and Techniques for Preventing and Treating Strain Aging

1. Ensure pure culture of the strains; be careful not to use strains contaminated by foreign microorganisms, and do not culture them connected at close range.

2. Strictly control the number of subcultures of the strains, reduce mechanical damage, and ensure strain vigor.

3. Preserve strains at appropriately low temperatures. For low-temperature-type strains such as the button mushroom (Agaricus bisporus) and shiitake (Lentinula edodes), 4°C helps preserve the vigor of the mycelium; for high-temperature-type strains such as the straw mushroom (Volvariella volvacea), 16°C helps preserve the vigor of the mycelium.

4. Avoid repeated subculturing in a single medium; strains should not be used for too long a period. Over-aged strains will show aging, and aging is organically linked to degeneration; strains with weak viability are very prone to degeneration.

5. Strains should be rejuvenated regularly, under conditions of suitable temperature, appropriate pH, sufficient oxygen, and culture free of foreign microorganisms.

6. Carry out spore isolation every year to discover superior strains through sexual reproduction, and use tissue isolation to consolidate the genetic characteristics of superior strains.