Antifungal activity in vitro of Rhus muelleri against Fusarium oxysporum f. sp. lycopersici

• Rhus muelleri extract inhibited 50% to Fusarium oxysporum at a concentration of 3363 ppm.
• Total phenols content in leaves and extract was 37.94 mg/100 mg and 33.94 mg/100 mg.
• The antioxidant activity in leaves was high in both assays evaluated for free radical scavenging.
• The antioxidant activity in the ethanol extract was higher than that found in the leaves of Rhus muelleri.
• Eight bioactive compounds were identified in the extract of Rhus muelleri leaves.

Fusarium oxysporum f. sp. lycopersici is the pathogen that causes one of the most destructive diseases of tomato. The use of plant extracts to control this disease is an alternative to synthetic fungicides. Rhus muelleri Stand et F. A. Barkley is a plant distributed throughout Sierra Madre Oriental and the Mexican Plateau. To date there is no information in scientific literature about the chemical composition and the biological activity of this species. The objective of this research was to evaluate the in vitro antifungal activity of R. muelleri extract against F. oxysporum and to obtain information of the extract chemical composition. The extract concentrations evaluated varied from 100 to 6000 ppm. The leaf extract yield was 37.43%. The R. muelleri extract inhibited F. oxysporum at MIC50 of 3363 ppm and at MIC90 of 11,793 ppm, representing an alternative to be used as a botanical fungicide. Eight bioactive compounds were identified on R. muelleri leaves by GC–MS analysis. The total phenolic content and the antioxidant activity in leaves and ethanol extract were higher than those reported in other Rhus species. This is the first scientific report on R. muelleri antifungal activity.