| In this research,the booming nanomaterial was introduced to control phytopathogens to investigate the inhibition effect of optimized synthesis of silver nanoparticles against Bipolaris maydis.There are four aspects to carry out:(1)Silver nanoparticles were biosynthesized using Ginkgo biloba fruit,and the optimum synthesis was achieved by adjusting the volume of fruit extract volume,concentration of AgNO3,and pH.The nanoparticles were characterized by UV-Vis,TEM,SEM,and EDX.(2)The inhibitory activity was conducted through colony formation,conidia germination,inhibition zone diameter,mycelia morphology,inhibition rate,and detached inoculation.(3)Analysis of inhibitory stability in condition of high temperature and ultraviolet radiation.(4)Synergistic antifungal effect of silver nanoparticles combined with four fungicides.The results showed that the optimal synthesis system contained 20 mL of fruit extract and 1 mM AgNO3 at pH 5.Under such conditions,synthesized silver nanoparticles were spherical or near spherical,the particles size was in the range of 8 to 24 nm with an average size of 14 nm.All of the 18 strains isolated from north of Anhui province were sensitive to prochloraz,and the most sensitive one was screened for further experiments.It expressed obvious antifungal effect for silver nanoparticles within the concentration range of 6.25～200 μg/mL.When the concentration of silver nanoparticles reached 200 μg/mL,the inhibition rate of colony growth and conidia germination was 78.7%and 100%.The mycelia morphology changed obviously,and fungus infection on the detached leaves was totally inhibited under the same concentration of silver nanoparticles.In addition,Prominent synergistic antifungal effect was found when AgNPs combined with selected fingicide.The toxicity ratio determined by Horsfall’s method reached 1.33,1.34,and 1.23 when the proportion of AgNPs and tebuconazole,propineb,fludioxonil was 1:1,9:1,and 7:3,respectively.Such research results not only provide a new idea for comprehensive control of B.maydis but slao resolve drug resistance to the utmost extent. |
