The USDA Should Let People Plant Blight-Resistant American Chestnut Trees
The American chestnut was once the dominant hardwood species in Appalachian mountain forests, comprising as much as 40 percent of the overstory trees in the climax forests of the Eastern United States. Foresters used to quip that an enterprising squirrel could travel from Maine to Georgia on the interlocking branches of chestnut trees. The fast-growing American chestnuts often reached five feet in diameter and 60–100 feet in height.
Then came the Asian chestnut blight in the early 20th century that killed over 3 billion American chestnuts basically causing the tree to become functionally extinct throughout its natural range. The blight fungus was probably brought to America on imported nursery stock of Chinese chestnuts. American trees had simply never evolved resistance to this parasite. The American chestnut is now almost entirely gone from the landscape except for a few stumps in the woods that still produce shoots that the blight kills before they reach 15 feet in height.
For more than 30 years, the American Chestnut Foundation (ACF) has been engaged in a privately financed program in which its geneticists have been crossbreeding American chestnuts with blight-resistant Chinese chestnuts. The goal is to produce an American chestnut tree that retains essentially only the blight resistance genes from the Chinese chestnut tree.
More recently, the ACF has been collaborating with researchers at the State University of New York’s College of Environmental Science and Forestry (ESF) to use modern biotechnology to endow American chestnut trees with blight resistance. To that end, the researcher
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