Considering the many different types of apples we see at farmers markets and supermarkets, it may be hard to believe that apple trees are not as diverse as they should be. But it isn’t the fruit-bearing part of the apple tree that’s the problem, it’s the apple tree’s rootstock.
Most of today’s commercially produced apples are from trees that were bred in two parts—the fruit-bearing scion that makes up the higher branches and tree tops, and the rootstock that forms the roots and lower trunk.
Most of those rootstocks are bred from “Malling 9.” Plant breeders at the East Malling Research Station in Kent, England, categorized Malling 9 for the first time in 1912. U.S. growers and others have widely adopted Malling 9 because it’s very productive and has important traits. That means most of our apple trees have roots that are derived from trees that grew as far back as the 17th century. “That’s really ancient technology,” says Gennaro Fazio, a plant geneticist and apple rootstock breeder with the Agricultural Research Service (ARS) in Geneva, New York.
To read the rest of the story, please go to: USDA Agricultural Research Service (ARS)
