Marker-Assisted Breeding in Horticultural Crops

Molecular markers of choice can be used for important functions in a breeding program including identifying outstanding parents, enhancing selection of elite alleles at loci controlling important traits, pyramiding favorable alleles at multiple loci affecting either a single trait or multiple traits and fingerprinting cultivars for identification and intellectual property protection. Assuming the goal of most breeding programs is release of improved germplasm or new commercial cultivars, marker-locus-trait combinations can be used as selection criteria to complement parent selection and selection in segregating populations during the commercialization cycle. These combinations should be not only biologically and technically feasible but also fundamental for outstanding cultivar performance in important target markets. Efforts to bring marker-assisted breeding (MAB) into wide adoption for horticultural crop improvement will benefit from targeted utilization of synteny among related crops and information from model plants to develop markers for use in standard breeding methods, e.g., backcrossing, and in new approaches such as genomic selection. Efficiency can be improved and some costs reduced in ongoing breeding programs by implementing MAB when important breeding issues receive appropriate attention.