Intraspecific Grafting of Tomatoes: Impact of Disease-Resistant Rootstocks on Fusarium Wilt Prevention, Plant Growth, and Fruit Quality under Naturally Infested Field Conditions

Fusarium oxysporum f. sp. lycopersici (Fol) is a soilborne pathogen that causes vascular wilt in tomatoes, severely affecting yield and quality. Grafting susceptible scions onto resistant rootstocks is a promising control strategy. This study evaluated four resistant tomato accessions (LE314, LE472, LE482, and LE501) for their ability to suppress Fol translocation and support scion performance. PCR analysis showed that all resistant accessions restricted Fol movement beyond the roots, with no detection in shoot tissues, indicating effective containment of the pathogen. Gene expression profiling revealed distinct temporal and accession-specific responses of LRR, WRKY41, and PR-1 genes. In field trials, heterografted tomatoes remained symptomless across planting years, while self-grafted plants exhibited severe wilt symptoms. All grafted combinations achieved 100% success without signs of incompatibility. Growth parameters (plant height, branch number, and canopy diameter), fruit size, and yield did not differ significantly between self- and heterografted plants. Importantly, fruit quality assessment indicated that specific traits, particularly total soluble solids and fruit firmness, were influenced by scion-rootstock interactions, while fruit pH and color attributes (L*, a*, b*) remained stable across grafted treatments. These results confirm that resistant rootstocks can prevent Fol infection and maintain agronomic performance, supporting intraspecific grafting as an effective and sustainable approach for managing Fusarium wilt in tomato production.