Key Technical Points and Detailed Methods for Mushroom Spawn Production

3. There are 3 methods for isolating mother spawn: spore discharge, tissue isolation, and substrate mycelium isolation. Here we mainly introduce the tissue isolation method. Tissue isolation method: cutting a small piece of tissue from each mushroom and transferring it onto a slant medium to culture into mother spawn. The fruiting body of an edible mushroom is actually a knot of dikaryotic hyphae, which has a very strong regenerative capacity. Therefore, as long as a small piece of tissue is cut and inoculated onto a suitable medium and cultured at an appropriate temperature, pure mycelium can be obtained. In tissue isolation, the selected mushroom is brought into a sterile room, and on an ultra-clean workbench, the cap and stipe are wiped with 75% alcohol cotton, then the middle part of the stipe is cut open with a flame-sterilized scalpel, splitting the mushroom body in half. At the junction of the cap and stipe or at the gills, a small piece of mushroom tissue is cut with an inoculation knife, then cut longitudinally into small thin slices of 5 mm x 10 mm. One thin slice is picked up with an inoculation needle and inoculated into the center of the slant medium, with one small thin slice inoculated per test tube. Once the hyphae germinate, mother spawn is obtained.

4. Culturing at an appropriate temperature: Place the above test tubes into a disinfected incubator or culture room for culturing, with the temperature controlled at around 25°C, so that the isolated spores or hyphae develop at an appropriate temperature. Two to three days after tissue isolation and inoculation, the hyphae germinate and spread and grow on the medium; after isolation and inoculation of the mushroom body, under normal circumstances the tissue block first turns dark brown, and after about 7 days white cottony hyphae grow on the cultured tissue block.

5. Purification of mother spawn: After the hyphae germinate, observe carefully and select pure-colored, robust, normally growing, and unbroken hyphal lines. On an ultra-clean workbench in a sterile room, hook out the hyphae together with the medium and inoculate them onto separately prepared test tube medium. Under constant temperature conditions of 23°C to 25°C, culture for 7 days to 10 days. After the hyphae grow over the test tubes, observe again and select the best ones for use; these are the "mother generation" mother spawn.

6. Subculturing of mother spawn: Under sterile operation, transfer one test tube full of hyphae into multiple test tubes for culturing. Generally, each tube of mother spawn can be expanded into 30 to 50 tubes, and those supplied in production are mostly progeny mother spawn. It can be subcultured and expanded again. Generally, each tube can again be expanded into 20 to 25 tubes of progeny mother spawn, but the number of subculturing times must not exceed 4. This is because too many subculture generations easily reduce the vitality of the spawn.

7. Fruiting test: Inoculate the mother spawn onto bottled or bagged sawdust medium, and according to the temperature requirements of the species characteristics of each mushroom, carry out culturing at an appropriate temperature, and only when fruiting occurs is it confirmed usable for production.

II. Propagation and Culturing of Stock Spawn

Inoculate the mother spawn onto bottled or bagged sawdust medium, and through culturing it becomes stock spawn.

III. Expansion and Culturing of Cultivation Spawn

Expand and inoculate the stock spawn again onto the same sawdust medium, and culture under appropriate temperature conditions for 30 days to 35 days to obtain cultivation spawn (also called production spawn), which can be used for production cultivation.