Methyl Anthranilate and γ-Decalactone Inhibit Strawberry Pathogen Growth and Achene Germination

Plant volatile compounds have been shown to affect microbial growth and seed germination. Here two fruity volatiles found in strawberry (Fragaria X ananassa), gamma-decalactone (peachlike aroma) and methyl anthranilate (grapelike aroma), were tested for effects on relevant pathogens and seedling emergence. Significant growth reduction was observed for Botrytis cinerea, Colletotrichum gloeosporioides, Colletotrichum acutatum, Phomopsis obscurans, and Gnomonia fragariae at 1 mM gamma-decalactone or methyl anthranilate, and 5 mM gamma-decalactone or methyl anthranilate supplemented medium resulted in complete cessation of fungal growth. Phytophthora cactorum was especially sensitive to 1 mM gamma-decalactone, showing complete growth inhibition. Bacteriostatic effects were observed in Xanthamonas cultures. Postharvest infestations on store-bought strawberries were inhibited with volatile treatment. The gamma-decalactone volatile inhibited strawberry and Arabidopsis thaliana germination. These findings show that two compounds contributing to strawberry flavor may also contribute to shelf life and suggest that gamma-decalactone may play an ecological role by preventing premature germination.