Genetic characterization of new source of resistance for tomato leaf curl New Delhi virus (ToLCNDV) from snapmelon (C. melo var. momordica)

Abstract This study aimed to understand the genetics of tomato leaf curl New Delhi virus (ToLCNDV) in the identified novel source of resistance from Indian melon germplasm DSM-19 ( Cucumis melo var. momordica ) as viral diseases in muskmelon cause significant economic yield loss. To achieve this, a cross was made between the highly susceptible genotype Pusa Sarda ( C. melo var. inodorus ), known for its desirable fruit characters, and the resistant source DSM-19 to generate the suitable populations for inheritance study. These populations were screened under natural epiphytotic conditions and further validated through challenge inoculation with viruliferous whiteflies. The inheritance of ToLCNDV resistance in snapmelon germplasm DSM-19 was identified as monogenic recessive in both the screening methods. Moreover, a cleaved amplified polymorphic sequence (CAPS) marker named ‘CAPS 16 (2)’ was designed near to SNP marker D16 located on chromosome 11 of melon, and it was found to be linked to the ToLCNDV resistance gene in DSM-19. This is the first report on genetics of ToLCNDV resistance in snapmelon germplasm from India. Snapmelon line DSM-19 can be used as a source for fine mapping and introgression of the ToLCNDV resistance into susceptible muskmelon cultivars.