Growth suppression of Fusarium culmorum, Fusarium poae and Fusarium graminearum by 5-n-alk(en)ylresorcinols from wheat and rye bran.

Alk(en)ylresorcinols (AR), a class of phenolic lipids, are regarded as antifungal compounds showing high potential for the use in plant protection, especially against Fusarium head blight (FHB). In view of the very limited knowledge of the activity of single AR against Fusarium species, the antifungal effect of crude extracts, fractions and isolated homologues from wheat and rye bran was determined. It was shown that the saturated AR are the active compounds in the extracts, whereas the presence of unsaturated molecules leads to an antagonistic effect. The activity of single saturated AR is dependent on the chain length, but for highest antifungal efficiency a mixture of saturated homologues is required. Affecting the stage of germination, these molecules reduce, and may even completely prevent, the growth of the tested Fusarium species.