Study On The Technology Of Mycelia Liquid Culture And Liquid Spawn Solidification In Stropharia Rugosoannulata

Stropharia rugosoannulata is an important cultivated edible mushroom.In recent years,S.rugosoannulata industry has played a crucial role in rural revitalization,especially due to its ability to efficiently convert and utilize various agricultural wastes,which presents a broad prospect for industry development.However,the lack of systematic research on liquid spawn production,quality evaluation,and application technology of S.rugosoannulata,as well as the drawbacks of traditional solid spawn in production and inoculation,have impeded the efficient cultivation and propagation of S.rugosoannulata.In this study,S.rugosoannulata SA09 was selected as the test strain,and multiple agricultural byproducts were used as raw materials to optimize the liquid culture formula for S.rugosoannulata mycelium.The image recognition technology for mycelial balls in liquid spawn was developed,and a preliminary quality evaluation model for liquid spawn was established.The liquid spawn of S.rugosoannulata was applied to the production of solid spawn（cultivation strain）.The main results of this study are as follows:（1）The raw materials for S.rugosoannulata mycelium liquid culture were screened,and the formula of the liquid culture medium was optimized.The optimal formula for S.rugosoannulata mycelium liquid culture was determined as follows:rice straw powder13.753 g/L,corn cob powder 9.059 g/L,wheat bran 8.867 g/L,K₂HPO₄ 1g/L,KH₂PO₄0.46g/L,MgSO₄·7H₂O 0.5g/L.（2）During liquid culture of S.rugosoannulata mycelium,sensory and quantitative characteristics were evaluated according to the current liquid strain evaluation criteria.The principal component analysis method was used to comprehensively evaluate the quality of the liquid strain based on 11 characteristic indicators,and three main factors were extracted:the growth factor（X₁）,mycelial distribution factor（X₂）,and mycelial ball morphology factor（X₃）.A comprehensive scoring function model Y=0.523X₁+0.364X₂+0.114X₃.The results showed that the diameter and density of mycelial balls,germination time on agar plates after transfer,and mycelial growth rate on agar plates after transfer were more critical for quality evaluation of liquid spawn.The model performed well and can be used to evaluate the quality of S.rugosoannulata liquid spawn.（3）Mycelial balls produced during liquid culture of S.rugosoannulata were collected,and their morphology was classified into four types.A mycelial ball dataset of F.velutipes was created,and YOLOv5 algorithm was used for image recognition training of mycelial balls to build a mycelial ball shape detection model.The results showed that the detection accuracy of the model reached 99.5%in mycelial ball object detection tasks,which can meet the requirements of mycelial ball shape recognition and lay the foundation for rapid detection of liquid strain quality.（4）Through single-factor experiments,corn cobs were selected as suitable raw materials for solidifying liquid spawns,and the key process for using liquid spawns to produce solid spawn（cultivated strains）was determined.Corn cob particles with a diameter of 4.75-8.46mm were used to fill 60%of the total volume of the spawn bottle,and reciprocating shaking was performed 25 times every 3 days during the cultivation period.Based on formula optimization,the optimal formula for producing S.rugosoannulata solid spawn from liquid spawn was determined as follows:corn cob 49%,peanut shell 49%,lime1%,gypsum 1%,moisture content 59-62%.The average time for seed preparation was 31days,which was 50%shorter than that for traditional solid spawn prepared during the same period.（5）The production and field application experiments of solid spawn（cultivated strains）produced from liquid spawns were conducted:Different sowing methods,including traditional solid spawn pit sowing,traditional solid spawn broadcast sowing,traditional solid spawn pit and broadcast sowing,and solid spawn broadcast sowing produced from liquid spawn,were tested.The results showed that the solid spawn broadcast sowing produced from liquid spawn had advantages in terms of mycelial germination speed,mycelial maturation speed,and fruiting period.It effectively avoided the weakening or death of mycelia caused by damage to the settled mycelia during S.rugosoannulata sowing.This significantly optimized the sowing process and improved the sowing efficiency.Based on the optimization of the S.rugosoannulata liquid spawn culture medium formula,this study developed an image recognition technology for S.rugosoannulata mycelial balls and established a quality evaluation model for liquid spawns.A technical system for producing solid spawn（cultivated strains）from liquid spawns was formed,laying a solid foundation for improving the quality and production efficiency of S.rugosoannulata spawns.