Chestnut trees were possibly on the cusp of revival, but a lab error undermined that project; future success is unclear

Few chestnuts ever reach maturity.
(Graphic by Adam Dixon, Ambrook Research)

A blight-resistant American chestnut seems a long way off despite years of dedicated scientific research and work to revive it.

The first epic chestnut loss goes back to the early 1900s when a deadly fungus, Cryphonectria parasitica, wiped out "5 billion trees and their 2 billion tons of biomass," reports Lela Nargi of Ambrook Research. But scientists at the State University of New York's College of Environmental Science and Forestry had been working to develop a genetically altered chestnut that could survive the blight, and their work showed progress until a lab blunder set the entire project into a tailspin.

Nargi explains, "This past December, SUNY admitted a major error with a variant known as Darling 58. This caused its research and financial partner, The American Chestnut Foundation, to pull its support of D58. . . ."

Not all chestnut tree supporters agree that genetic modification is the path to the trees' revival, but despite the controversy, SUNY put its first trees in the soil in 2006 and, by 2019, filed a petition with the Department of Agriculture to have D58 deregulated.

Things looked to be going well until the lab gaffe was aired. Nargi reports, "SUNY had goofed up variations of its breeding line. Instead of using D58 to pollinate trees in its research plots, it had accidentally used D54. . . .TACF withdrew its support of the petition and the trees themselves, saying they'd already noticed 'disappointing performance results.'"

Besides using genetic modification trees to bring back the chestnut, two other methods are in the works. "The American Chestnut Cooperators' Foundation seeks to breed resistance into 100 percent American chestnut trees," Nargi adds. "Another, undertaken by the American Chestnut Foundation, is a backcross in which American chestnuts are cross-bred repeatedly with Chinese chestnuts to impart the latter's blight tolerance into a hybrid tree." All the methods have problems, and while millions of wild chestnuts exist, few will reach maturity.

Donald Davis, author of The American Chestnut, told Nargi: "Even people who used to be fans of the American chestnut would say it had its chance, it had its place in history. They say now we need to move on to species that are going to be more likely to survive in new environmental conditions."