Impact of biosynthesized silver nanoparticles (AgNPs) on fusarium wilt disease in tomato: In vitro and In vivo studies Hafez, M. S., Abdou, El-S., Shaat, M. M. and Abd ElGawad, T. I. Plant Pathology Department, Faculty of Agriculture, Minia Universit

An isolate of Bacillus subtills was used as a bio-reducing agent to produce silver nanoparticles (AgNPs)., in which the cell-free supernatant as mixed with silver nitrate (AgNO3) in the reacting mixture (1:1). The biosynthesis was obviously observed by color change from white bale to dark brown and that was confirmed by UV-vis spectroscopy. Further examinations of AgNPs were made using SEM and TEM analysis. Nanoparticles showed a spherical shape with size in the range of 6-92 nm, and exhibition a slight aggregation. AgNPs have high potential to inhibit the growth: liner growth (cm) , dry weight (mg) two pathogenic isolates of Fusarium oxysporum grown on/in PDA media. Also, AgNPs gave significant protection against seed rot as well as the diseases incidence on tomato transplants. Moreover, the lower concentrations of AgNPs (12.5 and 25 ppm) have synergistic effect on seed germination and improve growth parameters of the roots and shoots growth.