Abstract
The effective use of Rhizopogon roseolus basidiospores in year-round crossbreeding programs largely depends on developing practical preservation methods that maintain their germination potential. Here, we assessed the germination capacity of this mushroom on 1 / 5 diluted modified Melin-Norkrans agar media following various storage conditions, including water suspension at 5℃ and -20℃, and preservation within frozen and dried tissues. Under optimal preservation conditions, we further examined the relationship between basidiospore maturity and preservation efficacy using basidiospores with low, medium, and high initial germination rates. While germination rates declined from fresh states, basidiospores preserved in water suspension at 5℃ for 6 months showed higher germination than the other preservation conditions. After 12 months in water suspension at 5℃, basidiospores of all maturity stages remained viable, forming colonies on 1 / 5 diluted modified Melin-Norkrans agar media. Notably, those with high initial germination rates retained higher germination than other stages. These results suggest that selecting R. roseolus fruiting bodies with basidiospores showing high germination potential before preservation in water suspension at 5℃ can enhance homokaryon production. This highlights the practical use of preserved R. roseolus basidiospores as inoculum in year-round crossbreeding programs.
Key words: Basidiospore germination, Crossbreeding, Ectomycorrhizal fungi, Mycelial colony, Nutrient agar medium
