Effect of Low-Dose Gamma Irradiation on Seed-Borne Transmission of Tomato Brown Rugose Fruit Virus in Tomato

Tomato brown rugose fruit virus (ToBRFV), a highly virulent tobamovirus, poses a major threat to global tomato production by overcoming host resistance and traditional control measures. This study evaluates the efficacy of low-dose gamma irradiation (10, 15, and 20 Gy) in reducing ToBRFV contamination in tomato seeds. Contaminated seeds were irradiated and assessed for germination rate, chlorophyll content, stem diameter, and viral accumulation with RT-qPCR. The potential synergistic effect of combining 15 Gy gamma irradiation with 2.5% sodium hypochlorite (NaOCl) was also investigated. Results revealed that 15 Gy significantly improved germination, enhanced chlorophyll levels, and increased stem thickness, while substantially reducing viral replication. In contrast, 20 Gy had detrimental effects on both plant growth and viral suppression. The combination of 15 Gy and NaOCl further decreased viral accumulation, though at the cost of reduced germination rates. The application of 15 Gy offers a dual benefit: effective seed disinfection and enhanced host resistance, positioning it as a promising component of integrated disease management programs in both greenhouse and open-field tomato production systems.