Synthesis of extracellular silica nanoparticles through bioleaching of sand by Fusarium oxysporum and nematicidal evaluation

Abstract

Meloidogyne javanica, a destructive soil-borne parasite that may infect practically all cultivated plants worldwide. Utilizing efficient bio-safe management techniques, crop damage caused by nematodes that feed on plants is reduced. Therefore, the aim of this study is to biosynthesize extracellular silica nanoparticles (SiO2-NPs) through bioleaching of sand by Fusarium oxysporum and characterizes SiO2-NPs and evaluates their nematicidal potential against M. javanica in vitro. During in vitro experiments, second stage juveniles (J2s) and egg masses of M. javanica were treated with various concentrations (50, 100, 150, 200 and 250 ppm of SiO2-NPs). All concentrations applied caused J2s mortality and inhibited egg hatching to a varying degree. The SiO2-NPs applied at same concentrations in addition predict preventing J2s from penetrating tomato roots. The characterizations of synthesized SiO2-NPs were done by XRD, FTIR, SEM-EDX, TEM-SAED, and UV Visible NIR Spectrometer. XRD technique analyzed amorphous phase of SiO2-NPs exhibiting a broad peak. The FTIR spectrum identified a range of efficient functional groups, capping and stability agents. TEM images of SiO2-NPs showed porous texture and had an average size of 22.5 nm. To our knowledge, this is first account of synthetic SiO2-NPs acting as natural nematicides through bioleaching of sand by F. oxysporum.