How to prevent pollution and understand the cultivation techniques of edible fungi in seed production of edible fungi

Seed production is a key link in the production of edible fungi. In the process of producing strains, improper operation, incomplete disinfection and other reasons will lead to the invasion of miscellaneous bacteria, pollute the strains, reduce the commodity rate of edible fungi and reduce the economic benefits. the common miscellaneous bacteria and control measures in edible mushroom production are introduced as follows:

Penicillium is the most common kind of miscellaneous bacteria. After contamination, it showed a small and separate green powder on the culture medium. Mildew spots. The bacteria are widely distributed and spread by the attachment of conidia in the air to wet materials that have not been thoroughly sterilized. Prevention and control measures: culture materials should be strictly disinfected; aseptic operation techniques should be strictly mastered during inoculation; ventilation, cooling and humidity reduction should be strengthened; local pollution can be washed with 5-10% lime water.

Second, Trichoderma is mainly green Trichoderma or Trichoderma koningii. It is transmitted by spores produced in organic matter cultures such as decaying wood, seeds, plant residues, compost and soil and floating in the air. The bacteria likes acidity, and it is easy to occur when the temperature reaches 25: 30 ℃ and the air relative humidity is 80: 90%. It can develop from the spot piece to the whole material surface in 3-5 days. Prevention and control measures: (1) strict disinfection of culture materials, complete elimination of hyphae and spores in culture materials, aseptic operation, strengthening ventilation and cooling. (2) the amount of formaldehyde used during disinfection should not be too much to prevent the formation of acidic environment. (3) when there is Trichoderma on the culture medium, apply 755 alcohol, 15% bleach powder, 50% carbendazim 200 times solution, spray 1% lime water or white ash powder and then dig, and then smear with lime water. During treatment, it is best to move the strain bag (bottle) outdoors to prevent the spores from flying. After the emergence of Trichoderma, it is strictly forbidden to open the bottle cap or open the film to avoid spread. When using plastic bags to produce seeds, it is not suitable to move too much during the cultivation period. (4) to remove the ungerminated bacteria in time. (5) the cotton plugs of the strain bottle and the strain bag should not be damp, and the culture room should be kept dry and clean. (6) the mother species should be pure. (7) add 25% (or 5%) 2 grams of carbendazim or 75 percent of tocopherol to 1 gram per kilogram of dry material.

Third, Mucor, Rhizopus and Aspergillus, also known as Mucor, mainly occur on the initial medium and strains of indoor cultivated mushrooms (ears). The hyphae were white or grayish white at the beginning, and then turned to light yellow. The hyphae are sparse and stout, and the roots can be seen clearly. The greater the water content of the culture material is, the more serious the occurrence is. The ability to decompose starch is strong and grows very fast. Prevention and control measures: (1) thorough disinfection, sterilization, do a good job of aseptic operation. (2) when mixing materials, add 2 grams of 25% (or 5%) carbendazim or 1 gram of 75% methyl topiramate per kilogram of dry material.

Fourth, Streptomyces is also called Neurospora, which can be harmful in the production process of all levels of bacteria. It is easy to happen especially when the temperature is high and the humidity is high. The bacteria is widely distributed in nature, and all kinds of organic matter, such as corncob, cornstalk, cottonseed hull, waste cotton and so on, are easy to occur. Its conidia float everywhere. Prevention and control measures: (1) do a good job in environmental hygiene, waste culture materials should be buried deeply. (2) the culture material should be sterilized thoroughly, the cotton plug should not be exposed to moisture, and should be replaced in time after being exposed to moisture. The strain bottle (bag) should be undamaged. (3) the inoculation room should be thoroughly disinfected and strictly abide by the aseptic operation rules. (4) sprinkle lime on the ground and, if necessary, sprinkle lime on the bottle mouth cotton stopper to keep it dry. After discovery, it was removed, burned, and sprayed with 75% wettable topiramate 500 times, or fumigated with 10 ml formaldehyde per cubic meter of space. (source: Gansu Farmers Daily)