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70 DECEMBER 2016 GOOD FRUIT GROWER www.goodfruit.com UPCOMING The RosBREED research group provides its next update in January. Stay tuned for more about RosBREED in future issues of Good Fruit Grower. "We really have had to build a network in the national and international community so that our growers are benefi ting from the antennae that are out in the world trying to get information and translate it to something meaningful," he said. "Breeding takes forever, but we're making rapid progress because of RosBREED. We're not all trying to build our own disease factory and breeding program. We're sharing a lot of information." In the future, once DNA markers associated with dis- ease resistance are identifi ed, people in the fi eld will be able to screen seedlings for disease by conducting a DNA test rather than by challenging the plant to the disease to determine if it carries resistant traits, said Jay Norelli, a plant pathologist at the U.S. Department of Agriculture's research station in Kearneysville, West Virginia. "We won't rely on the DNA tests 100 percent in the end, but the big cost in the breeding program is grow- ing material out in the fi eld," he said. "This way, we can start out with a much, much larger number of seedlings, screen them by DNA tests, and then have fairly good confi dence that the plant materials we're taking out in the fi eld and spending the money on are going to have the traits we want." Practical applications The genomic information gained from the RosBREED project is already being used to enhance breeding efforts for targeted crops across the country. Breeders now rou- tinely use genetic testing to verify parentage — some pro- grams have even discarded individuals in their programs after these tools showed unintended parentage. Parents are being selected using genetic tests in RosBREED breeding programs, for such things as fruit texture, fi rm- ness and size, storability, acidity and color, and some programs are already using genetic tests to cull seedlings. Researchers are trying the same approach to identify tolerance to 16 diseases in seven different crops, as well as prunus rootstock. Among them: Erwinia amylovora (fi re blight) in apple and pear (see "Tracking fi re blight" on opposite page), Podosphaera clandestina (powdery mildew) in sweet cherry and Blumeriella jaapii (leaf spot) in tart cherry. Iezzoni, who is leading tart cherry research, noted that while most tart cherries are highly susceptible to leaf spot, sweet cherries are tolerant. The fungus still enters the leaves of sweet cherry; however, the leaves simply do not yellow or fall off the tree as quickly. "There defi nitely is, in this genetic background, a cherry leaf spot tolerance, and the plant can continue photosynthesizing. It's just been remarkable," she said. She said she altered her breeding strategy this year to include the gleaned information. Ultimately, cultivars resistant to cherry leaf spot could translate to fewer sprays for a grower and less of a negative impact if they miss a spray for some reason. "Sometimes, this disease is not very forgiving if you miss a spray as the fungus gets well established in the tree," she said. "And this impact from disease resistant culti- vars could be repeated again and again thanks to help from RosBREED." RosBREED has provided breeders a new path forward to make breeding more effective and effi cient, she said. "We've learned about genetics, how to make changes in how we're breeding, and we're making progress that we would not have made without the grant." The results achieved already are proving the project very worthwhile, said Bill Dodd, an Ohio peach and apple grower and president of the Ohio Fruit Growers Marketing Association who serves on the RosBREED industry advisory panel. "I look at it from the big picture. We're headed down this highway, and our destination is better apples. We're making better stops along the way and gathering data along the way and gathering tools along the way, and from an overall view, it's doing what it's intended to do," he said. "The work they're doing is incredibly exciting." • Row Mulch Spreaders for All Growers Custom Built Equipment—Built to Last www.whatcommfg.com info@whatcommfg.com