Impact of AgNPs on Seed Germination and Seedling Growth: A Focus Study on Its Antibacterial Potential against Clavibacter michiganensis subsp. michiganensis Infection in Solanum lycopersicum

This study investigated the effect of biogenic AgNPs on seed germination and seedling growth of Solanum lycopersicum. Treatment with silver nanoparticles (AgNPs) showed a significantly high germination rate and seedling growth compared to untreated seeds. Furthermore, its bactericidal effect against bacterial pathogen Clavibacter michiganensis subsp. michiganensis (cmm) infection in Solanum lycopersicum was also determined. Bacterial canker of tomato (BCT) caused by cmm results in reduced plant growth and production leading to considerable economic losses. Herein, fungal extracts of T. harzianum and A. fumigatus were used separately as a reducing agent to synthesize AgNPs of varying concentrations (0.088 mg/L, 0.176 mg/L, and 0.44 mg/L). Results suggested that the biosynthesized AgNPs not only worked as bactericide but also completely inhibited the incidence of cmm infection even at the lowest concentration of 0.088 mg/L under greenhouse conditions. Plants treated with AgNPs showed significantly enhanced growth parameters including plant height (cm), tomato yield/plant (g), fresh biomass (g), number of shoots/plant, root weight (g), and dry biomass (g). So, in order to reduce the toxic effects of chemical-based bactericides, biobased AgNPs are recommended, not only to control but also to prevent the bacterial infection in agriculture.