How to cultivate high-quality oyster mushroom spawn? Master these three measures

Spawn is divided into mother spawn, stock spawn and planting spawn. They are also commonly called first-level spawn, second-level spawn and third-level spawn, and their cultivation methods differ. The technical key points are described below:

1. Mother spawn culture: refers to the spawn obtained by tissue isolation or spore isolation. The mother spawn medium is usually prepared with potato agar medium. To prepare 1000 ml of medium, use 200 g of potatoes, 18-20 g of agar, and 20 g of glucose.

Method: First wash and peel the potatoes, cut them into small pieces the size of broad bean grains, boil them in 1000 ml of water for 30 minutes, filter through 6-8 layers of gauze, and make up the lost water. Add the agar and let it dissolve, then add the dissolved sugar, and add water to bring the volume to 1000 ml. Then dispense into test tubes, filling each tube to 1/5-1/4, and add cotton plugs and wrap with paper. Sterilize at 1.2 kg pressure for 30 minutes, and while hot slant them to form slopes. After cooling, place at 25°C-27°C and observe; if there is no contamination, it can be inoculated. One tube of mother spawn can be transferred to 25-30 tubes.

The tubes inoculated under sterile operation are placed under constant temperature conditions of about 25°C for culture, and the mycelium can cover the tubes in about half a month. During the culture process, care should be taken to remove tubes contaminated by foreign bacteria. The well-cultured mother spawn is moved into a refrigerator and stored at 4°C for half a year, or stored at room temperature for three months.

2. Stock spawn culture: The raw materials can be sawdust or cottonseed hulls. Sawdust medium formula: sawdust 78%, wheat bran or rice bran 20%, sugar 1%, gypsum 1%. Cottonseed hull medium formula: use 50 kg of cottonseed hulls plus 3% potato extract liquid, (the filtrate from 1.5 kg of potatoes cut into paste and boiled for 30 minutes), sugar 0.1%, magnesium sulfate 0.1%.

Method: Add water to the culture material and mix evenly. The suitable moisture is when the material is tightly squeezed by hand and water beads are seen between the fingers but do not drip down. Generally, the material-to-water ratio is 1:1.2-1.3. Then fill bottles. The bottle-filling method is to gently shake the bottle while filling so that the upper and lower parts of the bottle are moderately compact. Fill up to the shoulder of the bottle and press the material flat, wash the culture material inside and outside the bottle mouth, add a cotton plug, wrap with paper and tie it well, then put it into a high-pressure sterilizer for sterilization, sterilizing at 1.5 kg pressure for one hour. After cooling, inoculate under sterile operating conditions. Insert the mother spawn from the test tube into the bottle. One tube of mother spawn can inoculate 4-5 bottles of stock spawn. After inoculation, place under constant temperature conditions of 25°C for culture for about one month, and when the mycelium covers the bottle, it is stock spawn.

3. Planting spawn culture: The preparation of planting spawn is actually an expanded cultivation of stock spawn. The formula of the sawdust medium for planting spawn is the same as that for stock spawn culture. The formula of the cottonseed hull medium is also the same as that for stock spawn culture. After bottling, sterilize, and under sterile conditions, inoculate the stock spawn into the planting spawn bottles. One bottle of 750 ml stock spawn can inoculate 80-100 bottles of planting spawn. After inoculation, place under constant temperature conditions of 25°C and cultivate for about one month; after the bottles are fully covered, they can be sown. When culturing stock spawn and planting spawn, after inoculation, check once every 2-3 days until the mycelium covers the material surface, then check once a week. Pick out spawn contaminated by foreign bacteria and dispose of it far away from the culture room.