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.
When all your trees grow on the same rootstock, it can make them all susceptible to the same diseases and pests, which can evolve, adapt and infect trees and tree roots that were previously immune. Malling 9 has never been very good at resisting diseases and pests, Fazio says.
Fazio and his colleagues are developing new apple rootstocks better equipped to resist pests and diseases. To ensure healthy trees, Fazio and his colleagues are looking to one of the ancestors of the world’s first apple trees, found in Kazakhstan.
ARS scientists brought back some trees from Kazakhstan in the 1980s and 1990s. Fazio crossbred some of the Kazakhstan rootstocks with rootstocks he had previously developed. He is screening 50 new apple trees by exposing them to some of the most destructive pests and diseases. He also has shipped some of the new rootstocks to commercial orchards around the world so they can be evaluated for different diseases, pest, soils, climates and rainfall patterns. Results so far show the Kazakhstan rootstock to be remarkably resistant to diseases and pests when it’s grafted to make trees producing Fuji, Gala and Golden Delicious apples, to name a few.
It takes years to develop quality apple rootstocks for commercial release. The key to apple breeding is ensuring a variety of quality rootstock is ready for apple producers when needed, and ARS scientists are doing just that.
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Very cool information! Love this and look forward to seeing these apples for sale someday!
This article brought to mind a PBS special program my husband and I watched about the seed "banks" located around the earth. The preservation of varieties of trees/plants capable of reproducing themselves is essential to future generations being able to feed themselves healthy foods. By being mindful of the condition of present food-stock and preventing catastrofic losses of species we are more likely to be able to feed future generations.
Your perspective from the roots up is a valid one. I am fascinated by the diversity of scientific approaches to the ancient need to feed people. Kudos! I am interested in your science.
I am part of Friends of the Cosmic Campground International Dark Sky Sanctuary (CCIDSS) cosmiccampground.org .We are trying to preserve and protect a small space in the Gila National Forest of New Mexico where world citizens can view a natural night sky. The day/night cycle has importance for the physical/emotional needs of all animals and plants.
Simple, sensible and fascinating propagation. Thank you