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Oral: Emerging Nano Materials for Disease Management and Insights from Findings in Nano-based Diagnostics


Advanced Nanomaterials for Management of Bacterial Spot of Tomato
A. STRAYER-SCHERER (1), Y. Liao (1), I. Ocsoy (2), M. Young (3), W. Tan (4), S. Santra (5), J. Jones (1), M. Paret (6) (1) Department of Plant Pathology, University of Florida, U.S.A.; (2) Department of Analytical Chemistry, Faculty of Pharmacy, Erciyes U

Bacterial spot caused, by Xanthomonas sp., is one of the most damaging tomato diseases worldwide. Due to the limited disease management options, growers rely heavily on copper-based bactericides, which are often ineffective due to the presence of copper-tolerant Xanthomonas strains. Separate studies were undertaken to characterize the antibacterial activity of advanced silver-based (Ag-dsDNA-GO), and copper-based (CS-Cu, MV-Cu, and FQ-Cu) nanomaterials as alternatives to copper. In vitro, Ag-dsDNA-GO and copper-based nanomaterials at rates as low as 10 and 100 µg/ml, respectively, killed all of the copper-tolerant and -sensitive X. perforans cells within 15 min and 1 to 24 h of exposure, respectively. In contrast, equivalent rates of metallic copper (up to 1000 µg/ml) from Kocide 3000 did not significantly reduce copper-tolerant X. perforans populations compared to the control at 72 h of exposure (P =0.05). In greenhouse studies, tomato plants treated with either 75 µg/ml of Ag-dsDNA-GO, 100 µg/ml of CS-Cu or MV-Cu, or 500 µg/ml of FQ-Cu prior to artificial inoculation significantly reduced disease severity when compared with copper-mancozeb and water controls (P =0.05). In a field trial, all of the copper-based nanomaterials significantly reduced disease severity when compared with water controls without a significant impact on yield (P =0.05). These studies highlight the potential of advanced nanomaterials for the management of bacterial spot of tomato.