For more than a century, scientists and conservationists have tried to bring back the American chestnut, a tree once so common it shaped forests across the eastern United States.
Now, Virginia Tech researchers and their partners have shown that genomic tools can dramatically speed up that effort, helping breeders predict which young trees are most likely to survive chestnut blight long before they reach maturity.
The new research shows that it is possible to identify blight-resistant trees that are still mostly American chestnut, preserving the height, growth, and forest competitiveness that made the species so ecologically and culturally important. By pairing large-scale field trials with genome sequencing, the team has created a road map for restoring the species more efficiently and at a much larger scale.
“This work changes how fast we can move,” said Jason Holliday, professor in the Department of Forest Resources and Environmental Conservation and a co-author on the study. “Instead of waiting years to see how a tree performs, we can use its DNA to predict resistance and make better decisions much earlier in the breeding process.”
The research was published on Feb. 12, 2026 in Science .
“Each American chestnut hybrid tree is a roll of the genetic dice,” said Jared Westbrook, director of science with The American Chestnut Foundation and lead on the project. “With DNA sequencing, we can quickly predict which individual seedlings are likely to inherit the greatest blight resistance from Chinese chestnut ancestors while also retaining the competitive growth form of American chestnuts.”
The American chestnut was once a dominant tree from Maine to Mississippi, valued for its fast growth, rot-resistant wood, and reliability as a food source. That changed in the early 1900s when a fungal pathogen, introduced from Asia, swept through eastern forests. Within decades, billions of trees were killed, leaving the species functionally extinct in the wild.
Since then, restoration efforts have focused on breeding American chestnuts with Asian relatives that evolved alongside the fungus and carry natural resistance. The challenge has been balance: Asian chestnuts are resistant but tend to grow shorter and behave differently in forests, while American chestnuts grow tall and fast but are highly susceptible to disease.
In the new study, researchers analyzed thousands of chestnut trees that had already gone through years of breeding and field testing by The American Chestnut Foundation. By sequencing their genomes and comparing genetic patterns with real-world disease outcomes, the team showed that resistance can be predicted using DNA data alone, an approach known as genomic selection.
“With genome-enabled breeding, we expect the next generation of trees to have twice the average blight resistance of our current population, with an average of 75 percent American chestnut ancestry,” Westbrook said. “The next generation of trees is expected to start producing large quantities of seed for forest restoration in the next decade.”
This range preserves the species’ characteristic height and growth and means breeders no longer need to rely solely on slow, labor-intensive methods such as infecting trees with the fungus and waiting years to see which survive. Instead, they can identify promising trees as seedlings and move them forward more quickly.
“The goal is restoring a tree that can actually compete in the forest and function the way the American chestnut used to,” said Holliday, also an affiliate faculty in Fralin Life Sciences Institute .
The study also examined a small number of wild American chestnuts that have survived decades of infection, known as large surviving American chestnuts. These trees are rare but they offer clues about whether any resistance exists within the species itself.
The researcher team, which included the HudsonAlpha Institute for Biotechnology, Oak Ridge National Laboratory, and the U.S. Forest Service, also was comprised of Qian Zhang, research associate in Holliday’s lab, and Alex Sandercock, a former Ph.D. student in Holliday’s lab, found that while some of these trees pass on modest resistance to their offspring, the effect is limited and inconsistent. That means they can contribute to restoration efforts, but they are unlikely to solve the problem on their own.
To better understand why Asian chestnuts resist the disease so effectively, the team produced some of the most complete chestnut genomes to date, including reference genomes for American and Chinese chestnut trees. The Virginia Tech research team found that resistance is not controlled by a single gene or simple switch.
Instead, it involves many genes spread across the genome, working together to strengthen cell walls, trigger chemical defenses, and slow the growth of the fungus. This complexity explains why resistance has been so difficult to breed using traditional methods and why genomic selection is such a powerful tool.
Together, the findings provide a scientific foundation for scaling up American chestnut restoration. Genomic selection allows breeders to move faster, maintain genetic diversity, and focus on trees that are both resistant and well suited for forest life.
While more work remains before large-scale reintroduction, the researchers say the tools are now in place to make meaningful progress within a generation.
“This is about giving restoration a real chance,” Holliday said. “We’re not just learning why the chestnut was lost. We’re learning how to bring it back.”
Science
12-Feb-2026