author(s)
Veeragoni Dileepkumar, Mutheneni Srinivasa Rao, Sunil Misra and Savarapu Sugnana Kumari

abstract
The present study was carried out in Indian Institute of Chemical Technology, Hyderabad during November, 2016-March, 2017 to investigate the antifungal activity of the three solvent extracts of seaweed Sargassum wightii against silkworm fungal pathogens. The crude seaweed compounds extracted with ethyl acetate, dichloromethane and diethyl ether solvents were tested at 1000, 2000 and 3000 µg mL^-1 for their antifungal efficacy in vitro and at 3000 µg mL^-1 against silkworm pathogens Aspergillus flavus, Nomuraea rileyi, Aspergillus oryzae and Beauveria bassiana in vivo. The data obtained was recorded for each trail in a one way ANOVA and was subjected with the Graph pad prism software analysis for its significance. Among the tested extracts maximum zone of inhibition of 20mm was observed in diethyl ether treated batches at 3mg/mL^-1 against Aspergillus flavus and 19.66 mm against Beauveria bassiana. In vivo results revealed maximum effective rearing rate of 84% in batch treated with diethyl ether against Aspergillus flavus followed by Nomuraea rileyi of 82 % and found to be significant at p<0.01. Sargassum wightii proved that the diethyl ether extract and ethyl acetate extract at 3000 µg mL^-1, showed varied degree of antifungal activity against silkworm fungal pathogens. Based on the results both diethyl ether and ethyl acetate extract of Sargassum wightii can be used as antifungal agents in preparing eco-friendly disinfectant in sericulture industry.