Arkansas fruit program included in second phase of USDA grant to advance marker-assisted breeding

Oct. 20, 2014
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By Fred Miller, Division of Agriculture Communications
479-575-5647, fmiller@uark.edu

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peach selection

Ph.D. student Alejandra Salgado, left, and undergraduate intern Lesley Smith mark peach trees selected by for advancement toward development as new commercial varieties. Information they collect on breeding lines helps validate genetic marker information being applied to the University of Arkansas System Division of Agriculture’s fruit breeding program as part of the USDA-funded RosBREED project.
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blackberry breeding

John R. Clark, University Professor of Horticulture and director of the University of Arkansas System Division of Agriculture fruit breeding program, has added blackberries to the genetic marker research being conducted in the USDA-funded RosBREED project.
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FAYETTEVILLE, Ark. — The University of Arkansas System Division of Agriculture fruit breeding program will expand its participation in the second phase of a USDA-funded research project to apply genetic marker technology to specialty crop breeding programs around the country.

The grant, awarded by the USDA National Institute of Food and Agriculture’s Specialty Crop Research Initiative, provides $10 million over five years for research to adapt and demonstrate new DNA-based tools in 22 U.S. fruit breeding programs. It focuses on eight crops: apple, blackberry, peach, pear, rose, strawberry, sweet cherry, and tart cherry.

John R. Clark, University Professor of Horticulture and director of the Arkansas fruit breeding program, will join project director Amy Iezzoni of Michigan State University and more than 30 scientists from 14 institutions in the project called “RosBREED: Combining Disease Resistance with Horticultural Quality in New Rosaceous Cultivars.”

“The goal of the project,” Clark said, “is to implement the use of DNA-based tools to complement the traditional breeding process by increasing the efficiency of breeding new peach and blackberry varieties with both superior product quality and disease resistance.”

Genetic markers serve as signposts that indicate desirable genetic traits in a plant’s DNA, Clark said. A marker may indicate a plant has resistance to a particular disease or that its fruit will be sweet or suitable for storage and shipping.

Years of genetic work in laboratories have identified a catalog of such markers. Clark said the RosBREED program’s aim is to put those tools to work in breeding programs like the division’s.

Clark said the Division of Agriculture participated in the first phase of RosBREED to identify molecular markers that control fruit quality traits in peaches. Years of genetic work in laboratories have identified a catalog of such markers.

Clark said the first phase of RosBREED was to identify and validate that these markers accurately depict their corresponding traits across a wide array of germplasm and then put those tools to work in breeding programs.

A set of DNA tests from this first phase of RosBREED are currently being validated to accurately depict these fruit quality traits across the Arkansas effort and three other U.S. peach breeding programs, Clark said. The second phase adds blackberries and peach disease resistance traits to the research.

“Once a genetic marker has been validated,” Clark said, “it can be used to select parents to cross together to combine desirable traits and increase the chance of more promising progeny.”

Later the marker can be used to determine in the greenhouse which seedlings from that cross contain the desired traits and which do not. That information helps Clark decide which seedlings to plant and which to discard. Seedlings planted in the field are then grown out to determine which have all the other desirable characteristics. From there, they are grown in replicated trials in different growing conditions and locations to confirm which are stable producers across environments.

Clark said graduate student Paul Sandefur began the work during his master’s degree program. Now, two Ph.D. students, Alejandra Salgado and Terrence Frett, are continuing the project and adding blackberries to the research. Once validated, those markers help Clark advance his conventional breeding efforts.

“I just charged them to bring me the answers,” Clark said.

The work is a Division of Agriculture team effort, Clark said. The graduate students are learning the genetic skills they need from Ainong Shi, assistant professor of horticulture and an expert in applying genetic tools to vegetable breeding. The students use Shi’s lab to run their DNA tests.

Program associate Andrew Jecman recently joined the horticulture department to bring his expertise in molecular technology to the fruit breeding program.

Clark said the Division of Agriculture was included in the RosBREED project because the project leaders recognize the quality of the Arkansas fruit breeding program. As a result, the program will be able to bring a host of new tools to the job of serving Arkansas fruit growers and consumers.

“All these tools help us get down the road to more efficient fruit breeding,” Clark said. “Producers will have more options to sustainably protect their crops, while consumers and the entire supply chain will directly benefit from products with better taste, nutrition, keeping ability, and appearance.”

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