Imagine the day when you can commercially grow fruit, nut, and ornamental cultivars that have high consumer acceptance, are highly productive, and are resistant to one or more major diseases. That hope may be one big step closer as scientists work together on a newly funded federal grant. On Oct. 2, the National Institute of Food and Agriculture Specialty Crop Research Initiative (SCRI) announced that a team working on the genomics, genetics, and breeding of crops from the Rosaceae family had been awarded funds for the first year of a $10 million, five year competitive grant.
This team is made up of 35 scientists from 14 U.S. institutions and includes numerous international collaborators. The project, entitled “RosBREED: Combining Disease Resistance with Horticultural Quality in New Rosaceous Cultivars,” will develop and apply modern DNA-based tools to deliver new cultivars with superior product quality and disease resistance.
Seeking Genetic Markers For Best Traits
This new project expands upon a recently completed 2009 SCRI funded project entitled “RosBREED: Enabling Marker-Assisted Breeding in Rosaceae.”
The focus of the first RosBREED project (RosBREED1) was on five rosaceous crops, namely apple, peach, sweet and tart cherry and strawberry. Scientists developed marker-assisted breeding (MAB) tools that are now being used to improve the efficiency and speed toward developing new and improved cultivars.
The genetic tests developed from RosBREED1 have enabled breeders to select for many important traits, in a number of crops including: apple (fruit texture and storability); peach (flesh type, acidity, soluble solids concentration, blush and bacterial spot resistance); sweet cherry (self-fruitfulness, ripening season, fruit firmness, and fruit size); tart cherry (fruit color and leaf spot resistance); and strawberry (everbearing fruit character and red stele root rot resistance).
Applying This Research
Breeders are now using DNA diagnostic information to more creatively choose parents for crosses and then select the resulting seedlings that contain or lack the desirable trait(s) in the greenhouse before they even flower. Seedlings lacking the desirable trait(s) are eliminated from future testing.
The resulting savings of time and effort allow resources to be reallocated to other critical activities. This is important when one considers that with traditional field screening at multiple sites (even states) it may take 25 or more years from the initial cross to the release of a new cultivar. In the case of the Honeycrisp apple, it was about 30 years from cross to release!
An equally important point, especially for crops with shorter generation times, is the pyramiding of alleles, something next to impossible without MAB. This is particularly relevant when trying to assemble new genotypes that have multiple desirable genes (e.g., an apple that is resistant to both fire blight and scab, plus having crisp flesh texture).
Industry stakeholders across the country have clearly highlighted that breeding for disease resistance is also critical for their long-term sustainability. This new project includes a core group of 15 U.S. breeding programs and activities with eight rosaceous crops. The critical disease threats that are being targeted and the estimated cost to stakeholders are noted in Table 1.
RosBREED2 brings a commitment to accelerating the development and commercialization of scion and rootstock cultivars with a focus on local/regional breeding programs. It brings together a team of scientists that are eager to work together to see the day when high quality, disease resistant fruit, nut and ornamental crops are no longer the exception, but the norm.