Method for preparing agaricus bisporus wheat grain strains, namely original wheat grain seeds, by utilizing white loam as filter layer

The invention provides a method for preparing agaricus bisporus wheat grain strains, namely original wheat grain seeds, by utilizing white loam as a filter layer. The method for preparing the original agaricus bisporus wheat grain seeds comprises the processing steps as follows: firstly, producing mother strains; and secondly, producing original wheat grain seeds. The method is characterized in that the processing step for preparing the original wheat grain seeds further comprises the steps as follows: material preparation is performed and includes that a wheat grain culture medium is processed and prepared, and sufficient natural white loam is taken for reservation; water content of the white loam is regulated in a range from 24% to 27%, and pH value is regulated in a range from 7.3 to 7.7; the wheat grain culture medium is bottled according to a conventional method, then the white loam is placed into a bottle from a bottle mouth, the placed white loam is located above the wheat grain culture medium and has a 4-5 cm distance away from the bottle mouth, and the thickness of the white loam ranges from 1.5 cm to 2 cm; inoculation is performed after sterilization treatment, that is, the mother strains are inoculated; and then the bottle containing original seeds well inoculated with the mother strains is placed in a culture room for cultivation according to the common method for culturing the original seeds. The method has an effect of filtering infectious microbes, infectious microbe contamination during a preparation process can be avoided to the greatest extent, and the rate of finished products can reach 99%-100%; and moreover, raw materials of the filter layer are easily obtained, and the cost is low.