Jornal de Patologia Vegetal e Microbiologia

Abstrato

Diospyros cuneata Inhibition of Fusarium oxysporum: Aqueous Extract and its Encapsulation by Ionic Gelation

Ruiz-Ruiz JC, Peraza-Echeverría L, Soto-Hernández RM, San Miguel-Chávez R, Pérez-Brito D, Tapia-Tussell R, Ortiz-Vázquez E and Rodríguez-García CM

The application of plant extracts to control fungal crop pathogens is an ecological strategy that could potentially be useful in agriculture. Aqueous extracts of some species of the genus Diospyros spp have been tested against fungal pathogens of crops. Nevertheless, there is no information about the inhibitory effect of aqueous extracts of Diospyros cuneata on the micelial growth of Fusarium oxysporum, a pathogen responsible for “Panama disease” and “vanilla stem rot disease”. Therefore, the antifungal activity of aqueous extracts of Diospyros cuneata leaves collected during the dry and rainy seasons was tested in-vitro against spores of Fusarium oxysporum. Only the aqueous extract from leaves collected during the dry season had an inhibitory effect on the micelial growth of asexual spores (2.5% minimum inhibitory concentration). Phytochemical analysis showed that both aqueous extracts contained mainly flavonoids and tannins; the chromatographic profile showed a larger abundance of polar compounds in the dry season extract. Furthermore, the antifungal activity observed is probably correlated with the abundance of some secondary metabolites produced by water stress and dry season conditions. Thebioactivityof aqueous extracts of Diospyros cuneata leaves could be stored and released through encapsulation; an effective example of this was tested using alginate-inulin to prepare microbeads by ionic gelation.