Stimulation of germination of teliospores of Uromyces appendiculatus by volatile aroma compounds

More than 100 aroma compounds were tested for activity in stimulating germination of teliospores of Uromyces appendiculatus, the fungus that causes bean rust disease. Preliminary volatility tests, in which teliospores on agar were exposed briefly to gaseous emanations from 10 μL of compound, were useful in quickly selecting stimulatory compounds for more detailed study. Of the various aldehydes, alcohols, esters, ketones, and isothiocyanate derivatives tested, several aldehydes and esters were effective. Isobutyraldehyde (55%), isovaleraldehyde (42%), and furfural (37%) stimulated germination. The esters methyl isobutyrate (60%), propyl propionate (54%), allyl butyrate (44%), and furfuryl propionate (28%) also stimulated germination