Issue link: https://read.dmtmag.com/i/787641
10 FEBRUARY 15, 2017 GOOD FRUIT GROWER www.goodfruit.com O ver generations, as breeders have selected apple trees with the best fl avor, size and color, resistance to many common dis- eases was lost. But genes for resistance are often still lurking in wild apple ancestors, and new DNA tools are giving breeders the power to return those key genes to domestic apple varieties in a matter of years, not decades. In the case of blue mold — the most signifi cant post- harvest disorder globally — scientists found resistance hiding in the genome of Malus sieversii, the wild Eurasian apple from which the domestic species was derived. Now, researchers with the U.S. Department of Agriculture's Appalachian Fruit Research Station in Kearneysville, West Virginia, are breeding that wild resistance back into an elite breeding parent. New tools are helping them to do it fast: Cultivars are expected to be ready for breeders in just a few more years, said Jay Norelli, the plant pathologist leading the project. "We are tapping into the latest advantages that have been made in genomics science to really advance the effi ciency of apple breeding," Norelli said. But while some of the tools used to expedite breeding are the result of genetic engineering, Norelli stressed that the process is not creating genetically modifi ed apples. The fi nal, blue-mold resistant cultivar will have no genetically modifi ed DNA. That's very important to growers because some consumers have been wary of genetically modifi ed crops, he said. Breeding teamwork All the genomics tools are available thanks to RosBREED — a national team of scientists seeking to improve the quality and disease resistance of apple, blackberry, peach, pear, rose, strawberry and sweet and tart cherry crops — and to a sister effort in Europe known as FruitBreedomics. The American project was funded by the U.S. Department of Agriculture fi rst in 2009 with a $14 million grant to look at fruit quality traits, then re-upped in 2015 for a $10 million focus on disease resistance. From the start, RosBREED has been clear that it was not seeking to genetically engineer better crops, but rather to use DNA analysis tools to inform and improve conventional crossbreeding, said Cameron Peace, RosBREED co-director and horticulture professor at Washington State University. Every generation, Norelli sends samples from his new seedlings to Peace's lab at WSU, where RosBREED's DNA-informed breeding programs for apple and cher- ries are based. The lab focuses on translating discoveries from genomics research into strategies breeders can use, Peace said. Taming traits from Special Report: Disease Resistance New genetic techniques have made it much faster for breeders to bring blue mold resistance from wild Eurasian apples into modern cultivars. by Kate Prengaman the wild genome