Monokaryotization by protoplasting heterothallic species of edible mushrooms.

After regeneration of protoplasts of seven heterothallic of edible mushrooms, two types of monokaryons were recovered, being identified by the absence of clamp connections. In regenerated colonies, monokaryons grew more slowly than dikaryons and so could be distinguished from them. In all species, the yield of monokaryons in the regenerated colonies was over 45%. The mating types and auxotrophic markers were the same in the protoplasted monokaryons and parental monokaryons. In comparison with other monokaryotization methods, protoplasting is rapid, simple and effective; its applications in breeding of edible mushrooms are discussed.