Molecular markers have been used widely for genetic mapping, identification and characterization of genes and QTLs for many important traits in vegetable crops, including biotic resistance, abiotic stress tolerance, and other morphological and biochemical traits. Marker assisted selection has been advocated as a highly efficient breeding tool, wherein genetic marker(s) (particularly DNA-based markers) tightly linked with the desired trait/gene(s)/QTLs are utilized for indirect selection for that trait in segregating/non-segregating generations. Under conventional breeding, gene pyramiding is very difficult because of some linked undesirable traits that are difficult to break even after repeated backcrossing. The advent and easy availability of molecular markers closely associated with each of the resistance genes makes identification of plants with multiple genes possible. Moreover, MAS can be competently used to select traits that are difficult to measure, having low heritability or expressed in later phase of development.