双孢蘑菇'申K6'种性改良的技术研究OA

Agaricus bisporus'Shen K6'is prone to strain degeneration during long-term preservation and large-scale cultivation.This study systematically evaluated three strain improvement methods,namely protoplast isolation,mycelial tip isolation,and single-spore isolation,by comparing vegetative growth performance,reproductive agronomic traits,and key lignocellulolytic enzyme activities.The results demonstrated that,at the vegetative growth stage,strains obtained via single-spore isolation exhibited significantly higher mycelial growth rates than those derived from the other two methods.A total of 80％of the single-spore isolates grew faster than the parental strain,with vigorous mycelia and fewer branches.By contrast,strains obtained by protoplast isolation exhibited higher consistency in colony morphology with the original'Shen K6'strain.At the reproductive growth stage,single-spore isolates possessed the best comprehensive fruiting agronomic performance.Compared with the parental strain,strain B9 presented a 28.9％increase in single fruiting body weight,strain B4 showed an 8.98％increase in pileus height,and B10 achieved a 35.55％improvement in total yield.Enzyme activity analysis revealed that among the three methods,mycelial tip isolation was most effective in enhancing lignin peroxidase activity,while single-spore isolation significantly enhanced cellulase and hemicellulase activities,which endowed the isolates with superior substrate utilization potential.Comprehensive evaluation of all indices confirmed that single-spore isolation is the optimal method for strain rejuvenation of'Shen K6',which can effectively improve mycelial growth vigor,fruiting yield,and substrate utilization efficiency.This study provides critical technical support for the long-term preservation and large-scale popularization of the'Shen K6'strain,as well as data references for strain improvement of industrially cultivated Agaricus bisporus.