Abstract
Germination of chlamydospores of Fusarium oxysporum f. raphani was examined on a glass microscope slide coated with collodion film.
The germination rate was slightly decreased at pH8.0, and was dependent on chlamydospore density in a mineral salts solution (BMS). Full dependence of the germination on exogenous glucose concentration was observed at higher densities (106/ml) of chlamydospore suspension.
Inhibition of the germination in lower concentrations of O2 was higher in BMS than in the BMS amended with glucose (BMSG).
Germination of chlamydospores in BMS was inhibited in the atmosphere of the Petri-dish with mycelial suspension of F. oxysporum f. raphani at the bottom. The inhibition was annulled in BMSG. Furthermore, the inhibition was more strong in the starved mycelium than in the non-starved mycelium, and was annulled when glucose was added to the mycelial suspension.
It is discussed that mycelium produces two types of volatile substances, the one of which is inhibitory for germination, the other stimulant. Production of these substances seems to depend upon carbon levels available for the fungus.
