The isolation and regeneration of protoplasts from the mycorrhizal fungi Lactarius piperatus and Suillus variegatus

An efficient system for the isolation and regeneration of mycelial protoplasts from the my­ corrhizal fungus Lactarius piperatus has been developed. The highest yield of protoplasts from the four-day cultures grown on solid media was 4x 107 protoplasts per milliliter. The protoplasts were stable and one hundred per cent viable. The regeneration achieved on a modified M-40 medium with 0.6 M KCl as an osmotic stabilizer was 55 %. Protoplast yields from the three-day liquid cultures of Suillus variegatus were 2. 7x 106 protoplasts per milliliter. In comparison with Lactarius piperatus they were very fragile and regeneration was not successful.