PURIFICATION AND PROPERTIES OF THE GERMINATION-INDUCING FACTOR IN THE ECTOMYCORRHIZAL FUNGUS LECCINUM-AURANTIACUM (BOLETACEAE)

A diffusion gradient bioassay on agar strips was developed for determination of the germination-inducing activity of exudates from mycelium of L. aurantiacum (Bull.) S. F. Gray on basidiospores of the same species. The taxon-specific germination-inducing factor, GIF, present in the active exudates, was non-volatile, diffusible, soluble in water, methanol and ethanol, resistant to boiling of short duration and stable after lyophilization if preserved at -20.degree. C. Gel filtration and adsorption experiments contributed to the chemical and physical characterization of GIF. Passage of an exudate through a Sep-Pak C18 minicolumn removed 99.5% of concomitant substances including germination inhibitors. GIF could then be eluted from the column with methanol without loss of activity.