The perfect peach, one that meets consumer preferences for flavor and texture and producer preferences for performance, remains elusive. Peach breeders are striving to fill this need; however, breeding a new peach cultivar is slow and inefficient, often requiring more than 15 years. Peach breeders have a hard time predicting which individuals would be the best parents and face the daunting challenge of selecting winners from populations of thousands and seedlings.
To efficiently and more rapidly deliver superior, commercially successful new cultivars, peach breeding programs need to implement new genetic technologies. Marker-Assisted Breeding (MAB), using DNA diagnostic information, is one such technology that is particularly effective to select parents and their offspring for desirable fruit quality traits such as size, color, flavor, and texture.
MAB can identify parental combinations that increase the probability of finding the most desirable offspring. Further, MAB increases the efficiency of selecting for target traits at the seedling stage, before plants are even planted in the field or nursery. This early screening reduces expenditures for planting, maintaining, and testing full-grown plants, an expensive and time-consuming proposition for peach. While this approach can enhance all rosaceous crop breeding programs, it is especially helpful in perennial rosaceous crops such as fruit trees, because it can take more than 25 years to develop and commercialize a new cultivar. Tools, knowledge, and training in this area were needed for Rosaceae breeding to capitalize on decades of upstream scientific advances.
“RosBREED: Enabling marker-assisted breeding in the Rosaceae” was funded by the USDA Specialty Crop Research Initiative. This project was dedicated to the genetic improvement of U.S. rosaceous crops by targeted applications of genomics knowledge and tools to accelerate and increase the efficiency and effectiveness of breeding programs. This multi-state, multi-institutional project focused on five rosaceous crops: apple, peach, strawberry, and sweet and tart cherry.
Within RosBREED, peach breeders in California, South Carolina, Texas, and Arkansas evaluated important parents, their ancestors, and their offspring for a range of fruit quality traits. Evaluating these individuals across these four very different sites added to our understanding of key traits and their interrelationships, making it possible to more efficiently improve them genetically.
RosBREED scientists developed DNA tests to predict peach maturity date and fruit quality traits including fruit texture, flavor, size, and skin color. These new genetic tests now help identify parents with the greatest likelihood of transmitting favorable traits, as well as pinpointing the best seedlings for further testing. All this reduces the effort and expense of growing out and sorting through thousands of seedlings with unacceptable fruit quality.
Peach breeders can now develop superior cultivars that meet the needs and desires of consumers and producers more efficiently, accurately and creatively. The impact is already being realized:
- Participating peach breeding programs have applied MAB since 2012 to choose better parents to result in superior offspring
- Corrected pedigrees of parents, selections, and seedlings enabled breeders to make well informed crossing, culling, and advancement decisions rather than partially informed guesses.
- MAB increased the efficiency of peach breeding programs by focusing resources on seedlings that have the greatest potential for commercial success.
Nine graduate students in RosBREED peach breeding programs have received state-of-the-art education in MAB.