Molecular characterization of Fusarium moniliforme and its management by methanolic extract of Coronopus didymus

摘要

Bakanae disease caused by different species of Fusarium, is one of the most emerging diseases of rice in Asia which is responsible for significant yield losses of this staple crop. The present study was designed to isolate and identify causal fungus and then the pathogen management by methanolic extract of a brassicaceous weed, Coronopus didymus. Based on cultural and morphological studies, isolated pathogen was identified as Fusarium moniliforme J. Sheld. Identity of the isolated pathogen was further confirmed by analysis of rDNA Internal Spacer Sequence (ITS) analysis. For preparation of extract, 200 g of C. didymus was soaked in 1.0 L of methanol for 14 days. Thereafter, material was filtered, filtrates were evaporated on a rotary evaporator and different concentrations (0.5 to 4%) of methanolic extract were prepared. These concentrations caused 23-48% reduction in the fungal biomass as compared to control. The inhibitory effect of 1.5% and higher concentrations was significant. Methanolic extract was subjected to GC-MS analysis and thirteen compounds were identified. Benzyl nitrile (34.22%), Eucalyptol (23.62%), 9,12,15-Octadecatrienoic acid, methyl ester, (Z,Z,Z)- (12.80%), n -Hexadecanoic acid (9.40%), Benzoic acid (6.89%), and 9,12,15-octadecatrienoic acid, (Z,Z,Z)- (5.18%) were the major constituents among the identified compounds.