Silver nanoparticles were biosynthesized using three plant extracts i.e., Neem, garlic, and lemongrass. Silver nanoparticles were formed by treating aqueous solution of AgNO3 with plant leaf extracts as reducing agent of Ag+ to AgO. The synthesized silver nanoparticles were characterized with transmission electron microscopy (TEM), Dynamic Light Scattering- nano sizer (DLS) and Zeta potential. In vitro, Neem AgNPs at concentration 800 µL/L inhibited completely the mycelium growth and sporulation of Fusarium oxysporum f.sp. lycopersici (FOL). Silver Nanoparticle synthesized by neem extract was the most effective treatments in decreasing disease incidence and severity. Moreover, increased the fresh and dry weight of shoot and root of treated plants. Results revealed that plants treated with silver nanoparticles exhibited an increase in activities of defense enzymes such as peroxidase, polyphenol-oxidase, chitinase, phenylalanine ammonia and phenol contents over the control plants. In this respect, silver nanoparticles synthesized by neem extract also were the best treatment. The present results suggest that silver nanoparticles synthesized by plant extracts had fungicidal activity, and it could be an efficient, safe and affordable alternative to chemical fungicides. |
