ANTIFUNGAL ACTIVITY OF METHANOLIC ROOT EXTRACT OF WITHANIA SOMMNIFERA AGAINST FUSARIUM OXYSPORUM F. SP CEPAE

Background: Basal rot of onion (Allium cepa L.) caused by Fusarium oxysporum f. sp. cepae is a common soil-borne disease that causes significant yield losses. Generally, synthetic fungicides are used to combat the menace which causes environmental pollution. The present study was carried out to assess the antifungal activity of Withania somnifera (L.), Dunal, a Solanaceous medicinal plant, against the pathogen of this disease. Materials and Methods: Different concentrations (from 0.5 to 4%) of methanolic extract of root stem and fruit of the test plant species were prepared and their bioactivity was assessed against the target fungal pathogen. Methanolic extract of root was further fractionated with n-hexane, chloroform, ethyl acetate and n-butanol. A range of concentrations of these extracts viz. 200, 100... 3.125 mg mL(-1) were prepared and assessed for their antifungal activities. Results: Methanolic root extract exhibited the best antifungal activity, causing up to 93% decrease in biomass of the fungal pathogen. n-hexane, chloroform and ethyl acetate fractions of methanolic root extract exhibited pronounced antifungal activity resulting in 46-79%, 40-73% and 35-76% reduction in fungal biomass respectively. Conclusion: The present study concludes that root extract of W. somnifera possesses potent antifungal constituents which can be used for the control of F. oxysporum f. sp. cepae.