Progressive degeneration of Cordyceps militaris during serial subculturing is associated with fruiting body decline and mating-type locus imbalance

Cordyceps militaris is a valuable medicinal fungus; however, large-scale cultivation is frequently constrained by strain degeneration during repeated subculturing. This study investigated the relationship between mating-type (MAT) locus imbalance and degeneration of C. militaris across seven consecutive subculture generations. Phenotypic characteristics, including mycelial growth, fruiting body development, biomass, and intracellular polysaccharide content, were evaluated alongside molecular analysis of MAT loci.