Harm and Control of Common miscellaneous bacteria in Edible Fungi

First, Alternaria. Also known as Neurospora. The asexual stage belongs to Trichoderma, Chlamydomonaceae; the sexual stage is a kind of ascomycetes. Pleurotus ostreatus is harmful to Alternaria crassa and Alternaria alternata. Hyphae white, lax, branched and septate. The conidiophores are bifurcated. Conidia series, globose to ovoid, orange or pink. Vesicles fascicled or scattered, subglobose or ovate. The ascus is cylindrical and contains 8 ascospores. Alternaria is widely distributed and can be spread in air, soil, rotten plants, grains and so on. Serious occurrence occurs when the culture material is too wet and the cotton plug is damp. It can pollute the mother, original and cultivated species of all mushrooms and the rods of Lentinus edodes, fungus and Tremella fuciformis. At the beginning of the contaminated bacteria and culture materials, the gray-white fine hyphae grew rapidly, and a few days later, orange powdery spores formed outside the bottle bag, which was obviously higher than the material surface. It often causes batch strains to be scrapped. The prevention and control methods are as follows: do a good job in environmental hygiene, sterilize the culture material thoroughly, avoid damp cotton plugs, and do not damage the bacterial bag during transportation. Strictly abide by the aseptic operating procedures, the culture room to avoid high temperature and humidity. Regular inspection showed that the spore clusters were covered with wet paper before being transported and burned.

Second, Trichoderma. Also known as green mold. Trichoderma, Cladosporaceae. Trichoderma viride and Trichoderma koningii are harmful to mushrooms. The hyphae are colorless and septate. Conidiophores arising from lateral branches of hyphae, erect, septate, branchlets often opposite, apical peduncles bottle-shaped, upper conidium. Conidia globose or ellipsoid, light green. The harm of Trichoderma to mushrooms is: polluting culture materials, competing with mushrooms for nutrition, secreting toxins, poisoning the hyphae of mushrooms, winding or cutting off the hyphae of mushrooms. It is widely distributed and is a harmful bacteria in the world. In order to damage for a long time, the growth process of mushroom is infringed. The degree of damage is so great that the whole batch of mushrooms can be destroyed. Trichoderma is found in rotten wood, plant residues, organic fertilizers, air and soil. After carbohydrate, too much material, partial acid and high temperature and high humidity environment are favorable for its occurrence. The residual roots left when picking mushrooms are easy to be infected. Prevention and treatment: keep the culture room at low temperature, low carbon dioxide and ventilation. Select varieties resistant to Trichoderma. The air humidity in the mushroom room should not exceed 90%. Remove the fragments and stubble in time after mushroom picking. At the initial stage of infection, 0.1% carbendazim or 800 times carbendazim was sprayed. Mixing with 0.1% carbendazim or methyl topiramate can prevent its occurrence.

Third, Penicillium. It also belongs to Trichoderma, Cladosporaceae. Those who harm mushrooms are Penicillium citrus, Penicillium flavum and so on. Hyphae colorless or colored, with transverse septum. Conidiophores are septate, upper broom-shaped branches, apex for small peduncles, peduncles series conidia, conidia spherical or elliptic, light green. Penicillium can grow on a lot of organic matter, and the conidia are mainly transmitted by air and can grow all the year round, especially in summer. On the contaminated culture material, round colonies were formed, from dark green to turquoise, fluffy, and expanded slowly. When the colonies are dense, they are connected into pieces. The old bacteria are often intertwined to form a membrane, which isolates the air on the material surface and secretes toxins, which has a lethal effect on the hyphae. It can also cause mushroom diseases. Control method: see the control of Alternaria and Trichoderma.

Fourth, Aspergillus. It also belongs to Trichoderma, Trichosporaceae. Aspergillus Niger, Aspergillus flavus and Aspergillus gray-green are harmful to mushrooms. The hyphae are colorless and septate. Conidiophores without septum, unbranched, apical expansion into spherical or elliptic, radial dense peduncles, conidia clustered on top, spherical or ovoid, black (Aspergillus Niger), yellowish green (Aspergillus flavus) or light green (Aspergillus gray). Aspergillus is distributed in soil, air and all kinds of organic matter. It is easy to occur when there are too many carbohydrates in the culture material because of high temperature, high humidity and poor ventilation. The contaminated culture material began to appear white velvety hyphae and soon turned into a colored powdery mildew layer. It not only competes with mushrooms for nutrients and water, but also secretes toxins, which seriously affects the yield and quality of mushrooms. Control methods: control of Alternaria and Trichoderma.