Can Increasing Strawberry Flavor Decrease Strawberry Pathogens?

Cultivated strawberries (Fragaria x ananassa) are known around the world for both their beauty and delicious flavor. Selection for flavor and disease resistance are both current breeding objectives, and may actually overlap in some cases. Previous reports have demonstrated that plant volatiles suppress growth of an array of fungal pathogens including Colletotrichum spp. and Botrytis cinerea. In the present study, we examined the in vitro effects of select strawberry volatiles on C. acutatum, C. gloeosporioides, and B. cinerea growth.  We have focused specifically on methyl anthranilate and structurally similar compounds including the fungicide Dichloran.  Methyl anthranilate produces a favorable “sticky sweet” flavor and is the key volatile of concord grapes.  Methyl anthranilate is absent in most octoploid strawberry genotypes and yet has positive organoleptic properties.  Our results show that methyl anthranilate is able to slow fungal growth in vitro. Its activity is approximately 10 times less effective than Dichloran, a structurally similar compound, at controlling fungal growth.  Another similar compound is anthranilic acid which differs from methyl anthranilate by a single methyl group.  Methyl anthranilate is >5 times more effective than anthranilic acid at controlling fungal growth.  The results indicate that methyl anthranilate and other volatiles may have anti-pathogenic roles in vivo. By extension, they suggest possible benefits of using plant volatiles to control pathogenic fungi with less environmental impact, while at the same time enhancing consumer-desired flavor of the product. Most importantly, they define an opportunity to breed for flavor and at the same time possibly breed for resistance to disease.