Index >> Mycorrhizae >> Resistance to Plant Diseases by Ectomycorrhiza

However, species of certain fungal genera causing ectomycorrhizae such as Lactarius, Cortinarius and Hygrophorus produce antibiotic substances while species of Russula produce none at all. Some of these antibiotics are antifungal on Rhizoctonia salani, Pythium debaryanum and Fusarium oxyporum. Neverthe­less, it remains to be seen whether antibiotics are elaborated by ectomyco­rrhizal fungi in vivo in association with the higher symbionts.
Boletus variegatus is known to produce volatile fungistatic compounds in pure culture. They have been identified as isobutanol and isobutyric acid. Infection of roots of Pinus sylvestris with B. variegatus resulted in the production and accumulation of volatile and fungistatic terpenes and sesquiterpenes to the extent of eight times the concentrations of such com­pounds in non-mycorrhizal roots.