Development of Cluster Tomato Varieties Resistant/Tolerant to Tomato Yellow Leaf Curl Virus (TYLVC) and Fusarium oxysporum f.sp. radicis-lycopersici (Forl) Through Molecular Marker-Based Plant Breeding

The global spread of viral and fungal diseases has led to a decline in tomato production as farmers are forced to abandon their crops. To combat these diseases, researchers have developed techniques using molecular-assisted selection to identify plant varieties that are resistant to these diseases. This study focused on cultivating cluster tomato varieties that are resistant or tolerant to Fusarium oxysporum f.sp. radicis-lycopersici (Forl) and Tomato Yellow Leaf Curl Virus (TYLCV) using molecular DNA markers. The breeding program involved isolating genomic DNA from 69 cluster tomato varieties and then using PCR with C2-25 and Ty3P6-25 primers to identify which varieties were resistant or tolerant to Forl and TYLCV, respectively. Out of the 66 cluster tomato varieties, 20 were resistant or tolerant (RR) to Forl, 37 were heterozygous resistant or tolerant (Rr), and 9 were susceptible (rr). Among the 3 cluster tomato varieties, some were resistant or tolerant (designated as RR) to TYLCV, while others were heterozygous resistant or tolerant (Rr), and some were susceptible (rr) to the disease. This indicates that DNA molecular markers can reliably determine the presence of resistance or tolerance to Forl and TYLCV in cluster tomatoes. Molecular markers can efficiently screen thousands of tomato plants in a shorter time period, leading to the selection of more high-quality, resistant or tolerant varieties.