Development of SCAR Marker Linked to Begomovirus Resistance in Melon (Cucumis melo L.)

Begomovirus is one of the most devastating diseases of melon causing high economic losses for farmers. The most ecofriendly strategy to overcome Begomovirus infection is to develop resistant or tolerant cultivar. However, this strategy is time consuming, expensive and complex, especially for hybrid selection process. A pair of Sequence Characterized Amplified Region (SCAR) marker was successfully developed from OPA-4 Random Amplified Polymorphisms DNA (RAPD) marker to discriminate potential Begomovirus resistant genotypes from the susceptible ones. Leaf samples were amplified using OPA-4 primer and produced specific band at 1198 bp. The band was purified from gel then sequenced. The sequence was analyzed and extended until 20 bp so it becomes a more specific SCAR marker. BLAST analysis showed that amplified sequence had 95.8 identity with Cucumis melo L. mitochondrial DNA. To ensure the consistency of marker, SCAR marker was applied in bulk F<inf>2</inf> plants. The results showed that the marker was consistent amplified same DNA fragment only in Begomovirus-uninfected samples. Chi-square test determined that the F<inf>2</inf> bulk segregated following 3:1 pattern for resistant. It was likely indicated that Begomovirus resistance trait was possibly controlled by single dominantgenes. Furthermore, this marker has been validated using eight different melon cultivars and confirmed not to be affected by environmental conditions. © 2021 Elsevier B.V., All rights reserved.