20Evaluation de l'éventuel effet antifongique de deux nanoparticules (ZnO et Fe3O4) vis à vis de Fusarium oxysporum, agent du flétrissement de la tomate, Solanum lycopersicum L.

Abstract

Tomato (Solanum lycopersicum L.) is a crop of major economic importance, but it is severely affected by vascular fusarium wilt, one of the most serious diseases of this species. In the search for alternative control strategies, this study was conducted to evaluate the antifungal activity of biosynthesized ZnO and Fe3O4 nanoparticles against two Fusarium oxysporum isolates. In vitro and in vivo assays were carried out using different nanoparticle concentrations. The in vitro study showed that treatment efficacy varied according to the type of nanoparticle, the fungal isolate, and the concentration, with the maximum effect consistently observed at 100%. F. oxysporum isolate 1 proved to be the most sensitive in vitro, particularly under the effect of ZnO nanoparticles, where growth was limited to 2.4 cm at 100%, compared with 4.2 cm for the control. Under the effect of Fe3O4 nanoparticles, it also exhibited marked antifungal activity, with a maximum inhibition rate of 64.29%. In contrast, F. oxysporum isolate 2 was less sensitive to the nanoparticles, which showed a weaker inhibitory effect. Both types of nanoparticles significantly reduced conidial production in the two F. oxysporum isolates. The in vivo study demonstrated that at 100% concentration, Fe3O4 nanoparticles provided durable protection and a stronger preventive effect than Trichoderma sp., effectively slowing down fusarium wilt development over three weeks. By contrast, ZnO nanoparticles lost their effectiveness over time, while the lower concentrations (25% and 12.5%) were insufficient to protect tomato plants.