An Environment Friendly Approach for Controlling Pathogenic Fusarium solani (Mart.) Sacc., The causal Agent of Root Rot of Medicinal Coleus by Methyl Jasmonate

Abstract

Effects of ‘methyl jasmonate’ were studied in vitro on colony growth, sporulation, spore germination and germ tube elongation of phytopathogenic Fusarium solani (Mart.) Sacc., the causal organism of root rot of medicinal Coleus. Three different concentrations of methyl jasmonate- 0.05%, 0.10%, and 0.20% were used as amendment with ‘potato dextrose agar’ medium. At 0.10% and 0.20% concentration, methyl jasmonate was able to significantly increase percent growth inhibition of the fungal colonies, as compared to the control, in a concentration dependent manner, after 48 and 96 hours incubation. Inhibition was more severe after 48 hours than 96 hours. Highest percent growth inhibition (76.00) was with 0.20% methyl jasmonate after 48 hours. Methyl jasmonate treatments also had significant reducing effects on spore formation, spore germination frequency and germ tube growth of the pathogen in a concentration dependent manner. 0.20% methyl jasmonate had most severe effects which caused lowest spore count (8 x 10 4 /ml culture filtrate), germination percent (4.80) and germ tube length (54.52μ). In the present study, methyl jasmonate showed fungistatic and fungicidal activity against Fusarium solani , under in vitro conditions. This is the first report of methyl jasmonate showing inhibitory effects on this particular fungus which in turn supports the possibility of future use of methyl jasmonate as a bio-control agent against root rot of medicinal Coleus caused by Fusarium solani , under field conditions.