Optimization, Characterization and Green Synthesis of Iron Oxides Nanoparticles Using Nerium Oleander Extracts and their activities against F. oxysporum f.sp. lycopersici After Genetic Diagnosis

Abstract

Background: Green-synthesized iron oxide nanoparticles may provide an eco-friendly approach for controlling fungal plant pathogens, such as Fusarium oxysporum f. sp. Lycopersici. Aim: This study aims at optimizing the synthesis and characterization of iron oxide nanoparticles utilizing Nerium oleander leaf extract and investigating its anti-fungal activity against the identified Fusarium oxysporum f. sp. lycopersici. Methods: Nanoparticles of iron oxide were prepared using a mixture of leaf extract of Nerium oleander. The optimization of synthesis parameters was done on the basis of pH (4, 7, and 10) and temperatures (30, 50, and 70°C). The nanoparticles were analyzed using ultraviolet-visible spectroscopy, atomic force microscopy, energy-dispersive X-ray analysis, field-emission scanning electron microscopy, and zeta potential analysis. The identification of fungus was done using PCR and sequencing of internal transcribed spacer (ITS). Results: The optimum conditions for nanoparticle formation were at a pH 4 and a temperature of 30°C, which resulted in the formation of spherical particles with an average size of 24.99 nm. The maximum absorbance was at 292 nm and the zeta potential was 20.9 mV. The percentage composition was made up of oxygen, carbon, and iron at 80.0%, 11.4%, and 8.6%, respectively. Internal Transcribed Spacer (ITS) sequencing showed 100% homology to F. oxysporum f. sp. lycopersici with GenBank Accession Number PQ060101. The inhibition zone diameters at 100, 200, and 400 µg/mL concentrations were 10, 14, and 19 mm. Conclusions: N. oleander-mediated iron oxide nanoparticles demonstrated concentration-dependent antifungal activity and may represent a potential green approach for controlling tomato Fusarium wilt.