The response of multi-disease and insect-resistant tomato lines to the accumulation of TYLCV, a whitefly-transmitted virus

Tomato (Solanum lycopersicum) is a major vegetable crop grown worldwide for its culinary versatility and nutritional richness. The whitefly-transmitted Tomato yellow leaf curl virus (TYLCV) poses a significant threat to its cultivation. The management strategies for this disease include controlling the virus and/or the vector. The multi-disease and insect-resistant lines developed by the World Vegetable Centre (WorldVeg) contain Ty-1/Ty-3 genes for virus resistance and WF2-10 and WF3-09 genes for whitefly resistance. This study evaluates the efficacy of suppressing virus accumulation in multi-disease and insect-resistant tomato lines compared to Ty-resistant or whitefly-resistant lines and a susceptible check. Preference bioassays, controlled inoculation with viruliferous whiteflies, and acylsugar quantification revealed that multi-disease and insect-resistant lines, developed at WorldVeg, had significantly higher acylsugar concentration and were less preferred by the whitefly adults for settling and whiteflies had high adult mortality. The multi-disease and insect-resistant lines also showed less severe disease symptoms and reduced virus accumulation over time when compared to Ty-resistant, whitefly-resistant, and susceptible check. The findings reveal that the multi-disease and insect-resistant lines are superior in mitigating the threat posed by TYLCV compared to TYLCV-resistant lines. These results underscore the potential of combined virus and vector resistance in tomatoes as a key element of Integrated Pest Management strategies against whitefly-transmitted TYLCV, offering a sustainable solution for safeguarding tomato production.