What are the biological characteristics of the nameko mushroom? A detailed explanation

The nameko mushroom, also known as sliding mushroom and shiny cap pholiota, is called nameko in Japan. Scientific name pholiotanamekio. In botanical classification, it belongs to the Fungi kingdom, Basidiomycota, Basidiomycetes, Agaricales, Cortinariaceae, and the genus Pholiota. It is a rare variety, originally from Japan; since the mid-1970s, it began in the southern region of Liaoning Province, and the current main production areas are northern Hebei, Liaoning, Heilongjiang, and other places. Since our county began large-scale production in 1989, utilizing local resource advantages and climatic advantages, and through continuous technological innovation by the broad ranks of scientific and technical personnel, the production volume and quality of the nameko mushroom have continuously improved, and it has now become the leading product of our county's edible mushroom industry. In 2004, output was 50,000 tons, accounting for 40% of national output and 25% of world output. It has become a good project for the broad rural areas of our county to escape poverty and become prosperous.

1. Biological characteristics

1.1 Nutrition The nameko mushroom is a wood-rotting fungus. In nature, it mostly grows on broadleaf trees, especially on the stumps and fallen logs of Fagaceae. For artificial cultivation of the nameko mushroom, sawdust, stalks, rice bran, wheat bran, and other agricultural and sideline products rich in lignin, cellulose, hemicellulose, and protein are used as artificial cultivation substrate. The nameko mushroom's demand for growth factors does not require additional supplementation in commonly used formulas with rice bran and wheat bran as the culture medium.

1.2 Temperature The mycelium of the nameko mushroom can grow at between 5°C and 32°C, with the optimum temperature being 22°C to 25°C. The fruiting body can grow at between 5°C and 18°C; above 20°C, the fruiting body cap is thin, the stipe is slender, and the cap opens early; below 5°C, growth is slow and basically does not occur.

1.3 Light Nameko mushroom cultivation does not require direct light, but there must be sufficient scattered light. The mycelium can grow normally in a dark environment, but light has an effect on inducing fruiting in physiologically mature nameko mushroom mycelium. During the fruiting stage, a certain amount of scattered light must be provided. If the light is too dim, the cap color is pale, the stipe is slender, quality is poor, and yield will also be affected.

1.4 Humidity The moisture content of the mycelium culture substrate is preferably 60% to 65%. During the fruiting body formation stage, the moisture content of the culture substrate is best at 75% to 80%, and the relative air humidity is required to be 85% to 95%.

1.5 Air The nameko mushroom is also an aerobic fungus, and its oxygen demand is related to respiratory intensity. In early spring, at the beginning of inoculation, the temperature is low, the mycelium grows slowly, and a small amount of oxygen can meet the need; as the temperature rises, mycelial metabolism accelerates, respiration increases, and mycelial mass increases, so attention must be paid to ventilation of the mushroom house and air exchange inside and outside the substrate bags. During the fruiting stage, the metabolism of the fruiting body is very vigorous, and fresh air is even more needed. If the carbon dioxide concentration in the environment exceeds 1%, the fruiting body cap will be small, the stipe slender, and the cap will open early.

1.6 pH The pH of the culture substrate directly affects the activity of cellular enzymes. The mycelial growth of the nameko mushroom requires a pH value of 5 to 6. The pH of culture substrate made from sawdust, wheat bran, and rice bran is generally 6 to 7, but after heating and sterilization the pH value will decrease, so there is no need to adjust the pH value again.

2. High-yield cultivation techniques

2.1 Cultivation season The nameko mushroom is a low-temperature, variable-temperature fruiting type fungus. In northern China, spring planting and autumn fruiting are generally adopted. For cultivation, semi-cooked substrate cultivation is suitable, and it is best to choose the early spring season when the temperature is below 8°C. The best sowing period is mid-February to mid-March.

2.2 Selection of superior spawn

(1) Variety selection Nameko mushrooms are divided according to different fruiting temperatures into very early-fruiting varieties (optimum fruiting temperature 7°C to 20°C), early-fruiting varieties (5°C-15°C), medium-fruiting varieties (7°C-12°C), and late-fruiting varieties (5°C-10°C). Producers should choose superior varieties according to local climate, cultivation method, and purpose. At present, the main cultivated varieties in the main production areas mainly include Zaofeng 112, c3-1, and others.

(2) Spawn selection When selecting spawn, it is required that it is not degenerated and not mixed. From its appearance, the mycelium is required to be white, fluffy, dense, uniform, and robust; the spawn age is required to be 50-60 days, not aged, not shrunken, and without water accumulation. When selecting spawn, various varieties should be used in combination and not a single variety alone, to prevent fruiting from being too concentrated and affecting product@#@136@#@.

2.3 Construction of the nameko mushroom fruiting shed A good cultivation site is the basic condition for the normal growth and development of the nameko mushroom. Under the current rural production level and economic conditions, generally simple facilities are used, making use of spare dwellings, and sheds or rooms are used as mushroom houses. Some also cultivate nameko mushrooms in air-raid shelters, mountain caves, and other places, and most adopt dual use of one site, that is, both a mycelium culture room and a fruiting room for fruiting body growth and development.

At present, standardized production generally uses louver-type fruiting sheds. The shed height is 3.5 m. The cultivation racks in the shed can be built in layers with wooden poles or bamboo poles. Generally, the rack height is 1.7 m to 1.8 m, the width is 0.6 m, the bottom layer is 0.2 m from the ground, and the spacing between layers is 0.3 m to 0.4 m. It is appropriate to set seven layers, with a 0.8 m aisle left in the middle. A structure using cement as upright posts and four No. 8 iron wires pulled as horizontal bars can also be used.

2.4 Commonly used formulas (1) Sawdust 77%, wheat bran (or rice bran) 20%, gypsum 2%, superphosphate 1%, pH 6.0-6.5, moisture content 60%-65%.

(2) Currently promoted formula: sawdust 84%, wheat bran or rice bran 12%, corn flour 2.5%, gypsum 1%, lime 0.5%, pH 6.0-6.5, moisture content 60%-65%.

2.5 Mixing materials Weigh the culture substrate in proportion, mix evenly, and add water according to the dryness or wetness of the raw materials so that the moisture content reaches 60%-65%, then pile and let stand for 30 minutes.

2.6 Sterilization (1) Use the loose-material sterilization steam type (inflatable boiler) layer-by-layer material scattering sterilization method. First spread a layer of gunny sacks on the steamer tray to prevent material from leaking. After the steam rises, spread culture substrate flat on the steamer tray to a thickness of about 6 cm to 8 cm (it must not be patted or pressed with hands or a shovel). When the steam rises strongly, use a shovel to scatter material layer by layer, making sure the material is scattered evenly and pressing down the steam. Load layer by layer in this way, filling to 8 parts full, that is, the material surface is loaded to 20 cm from the upper opening. Cover and press firmly, then blast with high heat until reaching 100°C, keep for 2 hours, then let stand for 30 to 40 minutes and take out of the pot while hot. Sterilization must be thorough. Each pot is suitable for sterilizing 200-500 trays (note: when coarse sawdust is used as the main material, the sterilization time should be extended).