Phylogenetic identification of fungi isolated from strawberry and papaya fruits and their susceptibility to fatty acids

Abstract

Strawberry (Fragaria × ananassa) and papaya (Carica papaya) are susceptible to fungal plant pathogens such as Botrytis cinerea and Colletotrichum spp., which are controlled mainly by chemical fungicides. However, their use causes adverse health effects. Therefore, the search for ecological alternatives is essential to reduce the impact of pesticides. This study aimed to identify Botrytis spp. and Colletotrichum spp. isolated from strawberries and papaya fruits with symptoms of gray mold and anthracnose disease and to evaluate the in vitro antifungal activity of different fatty acids on their mycelial growth. Phylogenetic analysis allowed the identification of Botrytis cinerea and Colletotrichum nymphaeae isolated from strawberry and C. siamense from papaya, which have been reported as pathogens of both crops. The in vitro antifungal index (AI) of the fatty acids was determined at concentrations of 100, 1000, and 2000 µM. Inhibition assays showed AIs of 100% for B. cinerea, C. nymphaeae, and C. siamense using decanoic acid (1000 and 2000 µM). Sodium octanoate (1000 and 2000 µM) and hexanoic acid (2000 µM) also inhibited C. nymphaeae with an AI of 100%. This is the first report on the antifungal effects of decanoic acid on three isolated fungi, as well as sodium octanoate and hexanoic acid, on C. nymphaeae. These results suggest that these molecules could potentially control diseases caused by these fungi in strawberry and papaya fruits.