Abstract

ANTIFUNGAL ASSAY BY POISONED FOOD TECHNIQUE

Geethanjali R., Aathiya Vanekar, Pratibha K. Y. and Marhoob Banu*

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Abstract

The present study was conducted with the main purpose to evaluate antifungal activity of four essential oils viz., Clove oil (Syzygium aromaticum), Eucalyptus oil (Eucalyptus globulus), Neem oil (Azadirachta indica) and Rose oil (Rosa rubiginosa) at concentrations of 20%, 40%, 60%, 80% and 100% respectively on Fusarium oxysporum by poisoned food technique. Screening of fungi on Sorghum vulgare (jowar) was done by agar plate method and the fungi studied was Fusarium oxysporum. Potato dextrose agar was prepared and well grown colony of Fusarium oxysporum was inoculated. Pure culture of Fusarium oxysporum was obtained by subculturing the previous culture and incubated at 27 ± 2 °C for 48 h. Fusarium oxysporum was suspended in sterile distilled water and adjusted to a standard inoculum size to 1-2 x 106 CFU/mL. Five different concentrations of essential oils were added to sterile potato dextrose agar at concentration of 500 ppm in the hood of laminar air flow and 0.1 ml of fungal suspension was used to inoculate treated PDA petriplates with a sterile non-toxic cotton swab. Acetone at 500 ppm was added as control. The treated plates with essential oils and control were incubated at 27 ± 2 °C for 7 days. After incubation the treated plates were observed for zone of inhibition around wells and also for complete inhibition. It was observed that rose oil and clove oil were effective in completely inhibiting the growth of Fusarium oxysporum while eucalyptus oil and neem oil showed zone of inhibition. Zone of inhibition was measured and recorded in millimetres (mm).

Keywords: Agar plate method, Antifungal activity, Fusarium oxysporum, Poisoned food technique, Sorghum vulgare.