Antimicrobial activity of silver nanoparticles (AgNPs) against Erwinia carotovora pv. carotovora and Alternaria solani

Abstract

Resistant plant pathogens have emerged against the conventional antibiotics. Alternative to these conventional antibiotics application of eco-friendly nanoparticles is an important strategy to manage plant disease. In the present research antimicrobial activity of silver nanoparticles (AgNPs) i.e. Ag, AgP, AgIB, AgAE and AgBE and antibiotics (Nystatin and Streptomycin) were evaluated against plant pathogens Erwinia carotovora pv. carotovora and Alternaria solani. The experiment was carried out in completely randomized Block Design (CRD) with three replications. The antibiotic Nystatin was used as a standard antibiotic reference in case of antifungal activity while streptomycin in case of antibacterial activity. For the antifungal and antibacterial activity different concentration were prepared as 150ppm, 200ppm and 250ppm and zone of inhibition(mm) for all silver nanoparticles (AgNPs) and antibiotics were prepared and inhibition zone was measured in millimeters(mm). Results revealed that the silver nanopartiles(AgNPs) i.e. AgAE and AgIB showed largest inhibition zone with the tested Erwininacarotovorapv. carotovora where the activity was 14.33mm and 13.13mm respectively followed by AgBE (10.40mm), AgP(10.33) and Ag(7mm) while the reference antibiotic streptomycin produced lowest inhibition zone(5.66mm). In case of Alternaria solani maximum inhibition zones were achieved from silver nanoparticles(AgNPs), AgAE and AgIB where the antifungal activity was 27mm and 24mm followed by AgBE(22.33mm), AgP(21.66mm) and Ag(18.66) while the reference antibiotic nystatin produced minimum inhibition zone(4mm). Further it was noticed that increasing the concentration of silver nanoparticles(AgNPs) significantly (P<0.05) increased the inhibition zones of the test plant pathogen and higher concentration(250ppm) posses strong antimicrobial activity. We can conclude that silver nanoparticles(AgNPs), had maximum inhibitory effect against Erwininacarotovorapv. carotovora and Alternaria solani when compared with the antibiotics