Penicillium, also known as blue-green mold, is a common polluting fungus in the process of edible mushroom seeding and cultivation, and under certain conditions, it can also cause diseases of edible mushrooms such as mushrooms, oyster mushrooms, anchovies, shiitake mushrooms, grass mushrooms and enoki mushrooms, and is a common pathogen that affects the yield and quality of edible mushrooms.
Symptom recognition
When penicillium occurs on the culture surface, the initial hyphae are white, the colonies are nearly round to amorphous, and the appearance is slightly powdery. With the large number of spores produced, the color of the colony gradually changes from white to green or blue. During the growth period, colony margins are often 1-2 mm white and spread slowly. The surface of the old colony is often intertwined to form a membrane, which is covered on the surface of the culture material, and secretes toxins to cause necrosis of the edible mycelium. In the process of seed production, if serious bacterial species are corrupted and scrapped; the germination period occurs heavily, it can cause the local material surface to not produce mushrooms.
Pathogenesis
Penicillium that harms edible mushrooms is a penicillium fungus. Colonies appear blue-green when the bacteria grow in large numbers. The pathogen is widely distributed, multi-saprophytic or weakly parasitic, exists in a variety of organic matter, produces a large number of conidia, mainly through the air flow into the culture medium, for the initial immersion. Raw materials and excipients with bacteria are also an important source of initial immersion dyeing for raw material cultivation. The conidia produced after immersion are re-impregnated with airflow, insects, artificial water spraying and management operations. High temperature is conducive to the onset of the disease, 28 °C -30 °C conditions are most likely to occur, conidia can germinate in 1-2 days to form white hyphae, and rapidly produce conidia. Most penicillium molds prefer acidic environments, and the culture material and cover are acidic and more susceptible to disease. Weak growth of edible mushrooms is conducive to the onset of disease, where the growth of young mushrooms is thin or the residual mushroom roots on the mushroom bed are not removed in time, it is conducive to the infiltration of pathogens.
Prevention and control methods:
(1) Conscientiously do a good job in disinfection and sterilization of inoculation rooms, culture rooms and production sites, keep the environment clean and hygienic, strengthen ventilation and ventilation, and prevent the spread of diseases.
(2) Adjust the appropriate pH of the culture medium. The culture medium for cultivating mushrooms, oyster mushrooms and shiitake mushrooms can be adjusted to slightly alkaline with 1%-2% lime water. After the mushroom is collected, lime water is sprayed to stimulate the growth of edible mycelium and inhibit the occurrence of penicillium.
(3) The local disease of the mold bag can be injected with 15% formaldehyde solution, and the penicillium can be washed with lime water when the penicillium bacteria occur in Duanmu, and the disease on the mushroom bed can be sprayed with 1% grammyldine, 0.5% duofengnong, 0.1% Shi Baogong and 0.1% parahynthenide solution.
Source: China Edible Mushroom Business Network