A new study published in the journal Science suggests that genetic testing could significantly speed up efforts to restore the American chestnut tree, which was driven to functional extinction by fungal blight and root rot in the mid-20th century. The tree once dominated eastern US forests, growing over 100 feet tall and producing vast quantities of nuts.
Researchers led by Jared Westbrook of The American Chestnut Foundation have sequenced the genomes of multiple chestnut species to identify genetic markers associated with disease resistance and growth. By testing individual trees, they can select those most likely to combine the desirable traits of the American chestnut with the disease resistance of the Chinese chestnut, which evolved alongside the pathogens.
The goal is to breed trees that retain 70-85% American chestnut DNA while resisting blight and root rot. Genetic testing allows breeders to identify promising offspring years earlier than traditional methods, shortening the generation cycle and accelerating restoration. The authors hope to see large numbers of disease-resistant trees in eastern forests within decades.
However, some experts urge caution. Steven Strauss of Oregon State University advocates for gene editing as a faster alternative, but notes that regulatory hurdles may delay such approaches. Environmental historian Donald Edward Davis questions whether hybrid trees can truly replace the ecological role of the original American chestnut, which was a keystone species supporting wildlife like squirrels and black bears.
