News

The macroscopic inspection of spawn quality can be summarized in five words: "pure, authentic, robust, moist, and fragrant." 

Specifically: "Pure" refers to high spawn purity, absence of contaminating bacteria, absence of inhibition lines, and absence of mycelial degeneration; "Authentic" refers to normal mycelium characteristics, exhibiting parental features such as pure white,

glossy, uniform growth, clustered growth, and elasticity; "Robust" refers to robust mycelium, vigorous growth, numerous and 

dense branching, and rapid germination, colonization, and spread on the culture medium; "Moist" refers to a moist substrate 

that adheres tightly to the bottle wall, with slight water droplets on the bottle neck, and no signs of drying or loosening; "Fragrant"

refers to possessing the characteristic aroma of the variety, without moldy, fishy, or rancid odors.

(I) Mother Spawn

High-quality mother spawn has pure white, dense, robust, uniformly growing mycelium with strong climbing ability, does not produce 

pigments, and grows rapidly, fully colonizing the culture medium in 5-7 days at 20-22℃. Excessive aerial mycelium forming a thick 

mycelial mat covering the tube wall indicates an aged strain or strain that has undergone multiple asexual reproductions; such strains 

are unsuitable for large-scale cultivation. Aged strains easily form primordia on the inoculum or test tube walls.

(II) Primary and Cultivated Strains

Excellent oyster mushroom primary or cultivated strains have white, robust, and dense mycelium with uniform and neat growth, resemblingcoarse wool. They exhibit strong climbing ability, do not easily form a thick mycelial mat, and have a strong aroma. Under conditions of 22–25℃, they generally reach full maturity in 30–35 days. Most varieties form fluffy aerial mycelium on the upper surface of the culture medium. In low-temperaturevarieties, the aerial mycelium often secretes yellowish-brown pigment, especially during hot seasons. Low-temperature varieties often exhibit reddish-brown or yellowish-brown aerial mycelium or yellow liquid, which is normal.

If a large number of coral-like fruiting bodies appear on the upper surface of the culture medium or fruiting bodies grow from the gaps in the bottle cap,it indicates that the strain is too old and should be used as soon as possible. If the culture medium dries out and yellow liquid accumulates at the bottomof the bottle, it indicates that the strain is too old and cannot be used. If the upper mycelium is sparse, dull, weak, and shriveled, while the lower mycelium is normal, it indicates that the initial culture temperature was too high, ventilation was poor, or there was bacterial contamination. If yellow, green, or orange-recolors appear, it indicates contamination by Penicillium, Trichoderma, or Neurospora, and the culture must be discarded. If the mycelium grows to about half itslength in the bottle and stops growing downwards, it indicates that the culture medium is too dry, too wet, or too compacted. In this case, the normal inoculumat the top can be used, and further cultivation should be discontinued.