Investigation of effects of silver nanoparticles againts Fusarium oxysporum f.sp. radicis-iycopersici jarvis & shoemaker'a in tomato

Silver nanoparticle (AgNP), a metal-based nanoparticle, is increasingly used for its antibacterial, antiviral and antifungal properties. Fusarium oxysporum f. sp. radicis lycopersici (FORL), is a tomato-specific harmful, soil-borne pathogen that causes high yield losses in tomato production. This study aims to determine the size of AgNP, which has the most effective inhibition rate on FORL, and to investigate its effects on tomato seed, primary plant and seedling in the presence or absence of this pathogen. In the first part of our research, the different sizes (3, 5, 8 and 10 nm) of AgNPs were applied to 6 different FORL isolates in vitro to determine the size and concentration for maximum inhibition. In the second part, different procedures were applied to seeds and seedlings of Narcan-8 and SC-2121 tomato species in vivo, and morphological, physiological and biochemical changes in plants were revealed. In vitro antifungal effect tests demonstrated that the application of AgNP in 3 nm size and 50 ppm concentration had an inhibitory effect of 99,4 % on mycelial growth of FORL. Following AgNP application, no significant change was observed in the germination percentage and viability index of tomato seeds. However, the morphological analysis showed that the applications of AgNP caused an increase in the primary root and stem length. The biochemical analysis revealed that there was a decrease in the amount of total chlorophyll, carotenoids and anthocyanins due to increase in the concentration. While the amount of H2O2, MDA, total protein and CAT decreased, the amount of GST, GR and POX enzyme activities increased. In large plant analyses, root and stem fresh weights and lengths increased. Further, H2O2, MDA, antioxidant enzymes and total chlorophyll content increased and decreased depending on the concentration and tomato type. As a result, it was observed that 37,5 ppm and 50 ppm AgNP applications in 3 nm size reduce the disease severity caused by FORL, and do not cause serious yield losses in the tomato plant caused by stress. It was concluded that aqueous dispersions containing 3 nm AgNP could be used as an effective and non-toxic preparation for the control of FORL.