Inoculated on sterile PDA plate medium with a diameter of 6 cm, cultured at 28 ℃ for 5 d, until the colonies covered the entire medium plate, and cut into tissues of about 0.5 cm × 0.5 cm under sterile conditions. The organization block is reserved. 60 g of rice and 80 mL of water were added to a 500-mL conical flask, wrapped in tin foil, sterilized by autoclaving at 121 ℃ for 20 min, taken out and placed at room temperature for later use. Inoculate the culture medium blocks with bacteria into the rice medium under aseptic conditions, 2-3 blocks per bottle, and incubate them at 28 ℃ for 30 d.