Hybrid analysis for ToLCV resistance in tomato (Solanum lycopersicum L.) andmolecular validation of Ty-3 gene

Tomatoes (Solanum lycopersicum L.) are widely recognized as a nutritious food due to their rich content of essential nutrients. Their growing popularity in recent years is largely attributed to lycopene, a powerful antioxidant known for its anti-cancer properties. However, the tomato leaf curl virus (ToLCV) represents a substantial risk to tomato crops at global level resulting in 100% crop loss. Therefore, the aim of this study was to develop and screen the tomato hybrids for ToLCV resistance and validate the presence of Ty-3 gene.The study involved evaluating 12 parents, 8 hybrids and 7 double cross hybrids carrying Ty-3 genes, which underwent screening at both phenotypic and genotypic levels. Assorted array of co-dominant sequence characterized amplified region (SCAR) markers were utilised to assess the resistance genes linked with tomato leaf curl virus (ToLCV), focusing specifically on Ty-3. The chosen markers P6-25, FLUW-25F and SCAR-1 demonstrated high reliability in distinguishing susceptible and resistant lines, facilitating the efficient identification of homozygous or heterozygous alleles relevant to ToLCV resistance. The screening resulted in the identification of three resistant parents (CBESL159, CBESL162 and CBESL169), two hybrids (H5-CBESL133×CBESL169 and H7-CBESL146×CBESL162) and two double hybrids (H5xH7 and H4xH5). These promising parents hold potential as parental materials for developing lines or hybrids with genes providing strong and enduring resistance against ToLCV and yield improvement. The double hybrids can be used for development of breeding lines.