5 Countermeasures to Prevent the Degeneration of Edible Fungi
The quality of edible fungus strains directly affects the cultivation results, that is, the level of yield, and is one of the key factors to generate economic benefits.
In actual production, some excellent varieties of edible fungi tend to degenerate within a few generations, which largely hinders the healthy development of the edible fungi industry. Strain degradation is a very prominent problem in the current production of edible fungi. To slow down or solve the problem of strain degradation of edible fungi to the greatest extent, it is necessary to understand the reasons for the degradation of edible fungus strains and prevent the degradation of the strains fundamentally. Here are some countermeasures to prevent the degradation of edible fungi for your reference:
1. Prevent the mixing of bacteria and ensure the pure culture of bacteria
In order to maintain sufficient genetic stability of excellent strains, the isolation of strains should be strengthened, and the mixing of strains should be prevented and reduced as much as possible in the transfer of strains to ensure the pure culture of strains. Do not use strains contaminated by miscellaneous bacteria, do not connect culture strains in close proximity, and do not mix different strains of the same edible fungus species.
2. Control the number of subcultures to ensure the vitality of the strains
There are spontaneous mutations in microorganisms, and this mutation occurs or appears during the reproduction process. The number of subcultures should be reduced as much as possible to avoid unnecessary transplantation and subculture. On the one hand, it can reduce mechanical damage and ensure the viability of the strains. On the other hand, it can reduce the probability of spontaneous mutation of the strains and reduce the chance of the strains declining. The more times the strains are passed down, the more frequent the reproduction, the higher the probability of mutations. The number of grafting generations of strains in production should not exceed 5 generations, and should be strictly controlled to avoid contamination by viruses or bacteria. Timely eliminate the mycelium and fruiting bodies that have a large content of virus particles and are seriously affected.
3. Do a good job of preserving the strains to delay the degradation of the strains
An effective strain preservation method can ensure that the strain maintains its original good properties for a long time, and delays and curbs the aging and mutation speed of the strain. Appropriate low-temperature preservation of strains is beneficial to preserve the vitality of mycelia. High-temperature strains are stored at 16°C, and low-temperature strains are preserved at 4°C. Strains should be preserved in a combination of short-term, medium-term and long-term. According to different requirements, the strains should be transplanted every 2 to 3 months during the cryopreservation period.
4. Create a suitable living environment and promote the robust growth of bacteria
Whether the growth and reproduction of bacteria is good or not is greatly affected by external conditions (physical, chemical and biological changes). If the conditions are suitable, the bacteria grow well, but if the conditions are not suitable, the bacteria will degenerate. To create a good living environment and nutritional conditions for the growth of the strains, a suitable culture medium for the strains can make the strains grow robustly, and too rich or insufficient nutrition is not good for the growth of the strains. Appropriate adjustment and replacement of the medium can rejuvenate the strains that have declined due to unsuitable nutrient substrates. In hot summer, adding an appropriate amount of vitamin E to the medium can delay cell aging.
5. Regularly isolate the strains and maintain the excellent properties of the strains
In production, asexual reproduction can maintain the excellent traits of the strain, and repeated asexual reproduction will make the excellent traits of the strain decline continuously. The spores produced by sexual reproduction are rich in genetic traits. Tissue separation (asexual reproduction) is used to consolidate the genetic characteristics of excellent strains, and spore separation (sexual reproduction) is used to discover excellent strains. The planned alternate use of sexual reproduction and asexual reproduction, and regular strain separation can restore the declining species, which is an effective way to prevent the decline of the strains. Spore isolation is performed once every 3 years, and tissue isolation is best performed once a year. Newly isolated strains must meet the requirements before they can be used in production.