Effect of resistance inducers on in vitro inhibition of mycelial growth and sporulation of Fusarium solani causing root rot of fenugreek

Fenugreek is a leafy vegetable plant known for its medicinal, pharmaceutical and nutraceutical properties.The root rot of fenugreek is more severe in recent years.Controlling this disease depends mainly on use of fungicides.The use of resistance inducers is an effective and nonfungicide alternative with antimicrobial properties and also induces resistance in plant.All isolates of Fusarium solani had potency to cause root rot disease but the isolate from Jaygaon locality was found highly virulent one and was selected for in vitro studies.The inhibitory effect of plant resistance inducers viz.chitosan (1-15 mg/ml), methyl jasmonate (1-20 mM) and salicylic acid (20-80 mM) on linear growth and sporulation of F. solani was evaluated by poisoned food technique.The obtained results showed that chitosan had significantly reduced linear growth and sporulation of F. solani with increase of concentrations when compared to control.The complete inhibition of both linear growth and sporulation was observed at 15 mg/ml and 10 mg/ml concentrations respectively.Methyl jasmonate (MeJa) had also significantly reduced linear growth in a concentration dependent manner.The highest fungal growth reduction (76.37 %) was observed with 20 mM concentration.It was interesting that MeJa had halted spore formation of fungus at10 mM concentration.The increasing concentrations (20, 40 and 60 mM) of salicylic acid (SA) were found to promote linear growth.However, 80 mM of SA had totally suppressed the growth of fungus.But, reduction of sporulation was found as SA concentrations increased over control.The results of current study showed the possibility of using resistance inducers to control Fusarium root rot of fenugreek.