Induction of systemic acquired resistance in Capsicum annuum L. against Chilli Veinal Mottle Virus by foliar spray of salicylic acid

Abstract

Management of viral diseases requires an integration of several methods aimed at preventing or delaying infection of crops, as the viruses overcome the resistance due to their genome plasticity. Plants have evolved a variety of active and passive mechanisms to defend themselves against viral pathogens. One such mechanism is systemic acquired resistance; a safekeeping system a plant has preserved to combat various pathogen attacks. The possibility of inducing resistance in plants against viruses with chemicals or beneficial microorganisms deserves more interest. This study was conducted to evaluate the efficacy of salicylic acid (SA) foliar spray against Chilli Veinal Mottle Virus (ChiVMV) infecting Capsicum annuum L. which induces systemic acquired resistance. Salicylic acid was used as a foliar spray in different concentrations against ChiVMV with reference to disease incidence, percentage inhibition of virus, virus quantification, plant growth and yield parameters, and internal SA accumulation, under pot conditions. Minimum disease incidence and maximum percentage inhibition were recorded when plants were sprayed with 100 ppm salicylic acid 24 h before challenge inoculation. SA 100 ppm foliar spray not only delayed the virus symptoms but also reduced the virus concentration with enhanced growth and yield. Exogenous SA increased the internal SA accumulation, a key factor for SAR.