Ação antifúngica do estrato de Physalis peruviana Linnaeus frente ao fungo Botrytis cinerea

Abstract

The chemical composition of strawberry (Fragaria x ananassa Duch) contributes to the development of fungi, in particular Botrytis cinerea, the main phytopathogen related to the crop. This is responsible for causing gray mold, the main fungal disease that affects fruits, especially in the post-harvest period. The severity of the disease is due to the ability of Botrytis cinerea to remain in the fruits throughout the maturation period, only to occur in the post-harvest period, which results in considerable economic losses for the productive and commercial sector. The control of the fungus is carried out mainly by synthetic fungicides, indicated for application from the beginning of flowering to the period of pre-harvesting of the fruits. Alternative methods of control have been used in order to reduce the incidence of the disease, but Botrytis cinerea's own characteristics make it highly resistant. These factors, coupled with the high levels of fungicide residues in fruits and the search for the development of healthy foods, have intensified research to identify new methods of Botrytis cinereacontrol. Extracts obtained from plants have aroused the scientific interest to contain substances responsible for protecting them. This action is due to the presence of secondary metabolites capable of exerting antimicrobial action against a range of microrganisms. The presence of phenolic acids and flavonoids in different parts of the fruits of Physalis peruvianaconfer the ability of the species to act as a natural antimicrobial agent. To evaluate the preventive action of the extract of Physalis peruviana on the fungus Botrytis cinerea, applied by suspension of conidia in the concentration of 105 conidia per mL of suspension, in strawberries of the Albion variety was the general objective of this dissertation project. Application of the extract preventively against the fungus demonstrated a better antifungal action when applied to green strawberries stored at 25 °C. The chemical composition of strawberries possibly interferes with the intensity of the action exerted by the extract.Phenolic compounds, chlorogenic acid (148.8 μg mL-1), caffeic acid (14.42 μg mL-1), ferulic acid (2.44 μg mL-1) and quercetin (190 μg mL-1) identified in the extractexert an antifungal action on the fungus Botrytis cinerea, possibly due to the synergistic action of the three compounds. Physalis peruviana represents an alternative for preventive control of gray mold in strawberries of the Albion variety.