Enabling Marker-Assisted Seedling Selection in the Washington Apple Breeding Program

Breeding new cultivars is a slow and expensive process, but genetic screening tools exist to improve efficiency. We employed the marker-assisted breeding (MAB) Pipeline approach to facilitate routine use of MAB in the Washington apple breeding program. This study traced the journey of one marker-locus-trait (M-L-T) association from publication through high-throughput PCR-based genetic testing to application. The final stages of the Pipeline involve determining cost-efficient high-throughput marker-assisted seedling selection (MASS) schemes with available genetic tests, followed by a trial run on several thousand seedlings. For maximum cost-efficiency in the Washington apple breeding program, genetic screening should be implemented prior to expensive grafting and field planting operations but usually after inexpensive visual culling for traits such as disease susceptibility. Routine MAB is now enabled for this tree fruit breeding program and we estimate that at least 60% of conventional operating costs for first-stage seedling selection could be saved using the available genetic test.