US EPA

2280869 

Journal Article 

Bioassay Guided Fractionation of Withania somnifera for the Management of Ascochyta rabiei 

Javaid, A; Munir, R 

2012 

Yes 

International Journal of Agriculture and Biology
EISSN: 1560-8530 

FRIENDS SCIENCE PUBL 

FAISALABAD 

14 

5 

797-800 

English 

WOS:000309210600019 

Withania somnifera (L.) Dunal., a medicinal plant of family Solanaceae, was used to examine its antifungal activity against Ascochyta rabiei, the causal organism of highly damaging blight disease of chickpea (Cicer ariatinum L.). In laboratory screening bioassays, different concentrations (0.2, 0.4, 0.6, 0.8, 1.0 g 100 mL -1) of methanolic extracts of stem, root, leaf and fruit of W. somnifera were evaluated for their antifungal activity against the targeted fungal pathogen. The methanolic extracts of fruit and leaf were found highly effective against A. rabiei causing up to 41% and 43% suppression in fungal biomass, respectively. The methanolic extract of fruit was further subjected to fractionation by using n-hexane, chloroform, ethyl acetate and n-butanol in order of increasing polarity. Different concentrations (3.125, 6.25, ..., 200 mg mL -1) of these fractions were used against the test pathogen. Ethyl acetate fraction was found highly effective against A. rabiei exhibiting complete inhibition of fungal growth. Two compounds namely A and B were isolated from this fraction through thin layer chromatography (TLC). These compounds were then appraised to find minimum inhibitory concentration (MIC) against the test fungal pathogen. Compound B was found more effective than A. The MIC values of compounds B and A were 62.5 Hg mL -1 and 1000 Hg mL -1, respectively. It was concluded that antifungal compounds B could be used for the management of A. rabiei. © 2012 Friends Science Publishers. 

Ascochyta rabiei; Blight; Chickpea blight; Natural fungicides; Withania somnifera