اثر افزایشی نانوذرات نقره بر القای مقاومت گیاه گوجه فرنگی به خسارت ناشی از شب‌پره Tuta absoluta

The tomato leaf miner, Tuta absoluta, is one of the important pests of the plants belonging to the Solanaceae family, especially tomatoes, which can destroy the entire crop production if not controlled. One of the control methods against this pest is to use silver nanoparticles. In this research, the tomato plants were exposed to 200, 400, 600, and 800 ppm of silver particles with sizes smaller than 100 nm. For biological studies, the cohorts of 30 adult moths were released to the cages containing treated tomato plants with each concentration in the constant laboratory conditions (25±2°C temperature, 60±5% relative humidity, and 16:8 hours L: D) to lay their eggs. After 24 hours, the adults were removed and the fertility rate, egg mortality, and larval survival were checked. Also, the amount of total phenol, and the activity of enzymes peroxidase (POD), polyphenol oxidase (PPO), superoxide dismutase (SOD), and catalase (CAT) of the tomato plant were measured to determine the possible reason for the increased resistance of the plants to this moth. The experiments were performed in three replicates and distilled water was used instead of silver nanoparticles in the control treatment. According to the results, the number of eggs laid in the treatments decreased significantly. In addition, the nanoparticles increased the mortality of embryos and larvae of the moth (P < 0.05). The maximum mortality of the eggs and larvae in the 600 ppm treatment was 59.60% and 67.48%, respectively, and in the 800 ppm treatment, 59.68% and 63.26%. However, there was no significant difference between these two concentrations. Also, the enzymes SOD and PPO were enhanced significantly in all treatments (P < 0.05). This enhancement in the plants were treated with 600 and 800 ppm was higher than the others. In addition, the amount of phenol in the tomato leaves treated with 800 ppm was measured as 0.38 mg/100g FW which was significantly greater than other treatments (P < 0.05). Therefore, silver nanoparticles can protect tomato crops from damage caused by T. absoluta by inducing and increasing resistance in the plant. They can serve as an alternative to common insecticides in the future.