Aims: This study aimed to isolate the fungal strains causing brown spot disease on dragon fruit and identify them using molecular biology techniques. The study also investigated the inhibitory effects of silver (Ag) and ZnO nanoparticles on the isolated fungal strains.
Methodology and results: Six fungal strains (TL1, TL2, TL3, TL4, TL5, TL6) causing brown spot disease (stem-canker) were isolated. TL1 and TL2 isolates were used for testing the antifungal features of nanoparticles. Nanoparticles were directly added to the PDA medium to make a solution with concentrations of 50, 75 and 100 ppm. The antifungal feature of nanoparticles was screened by inoculating with the fungal samples for 72 h. The inhibitory capacity of ZnO and Ag nanoparticles against fungal strains was then investigated. TL1 and TL2 samples were identified as Neocytalidium dimidiatum using the internal transcribed spacer (ITS) region. The study also revealed that silver nanoparticles were more effective than zinc oxide nanoparticles in inhibiting the growth of fungal strains that cause brown spot disease on dragon fruit. Specifically, ZnO nanoparticles had the highest inhibitory effect on TL2, 61.27% at 100 ppm and Ag nanoparticles gave the highest inhibitory effect on TL2, 85.83% at 100 ppm.
Conclusion, significance and impact of study: The research findings suggest that the use of Ag and ZnO nanoparticles may be an effective way to control brown dragon fruit spot disease. It may help in improving dragon fruit yield and aesthetic quality. As a result, it may help in reducing economic loss for farmers. However, further research is required.