Efforts to restore American chestnut trees to their rightful place in the North American forest ecosystem are progressing, although progress has come at a slower pace than once expected, according to researchers in Penn State’s College of Agricultural Sciences, who explain they have reached a pivotal point.
The 27-year-old traditional breeding program, which has attempted to infuse blight resistance from the Chinese chestnut tree into American chestnuts, is receiving a boost from tree molecular geneticists at Penn State and five other universities working collaboratively in a bid to improve the process. While traditional breeding has been taking place, so have parallel lines of research into genetic modification and also bio-control of the fungus that causes the blight.
“Teams of researchers are now at a crossroads where all three methodologies may be combined to provide a more robust product,” said Sara Fitzsimmons, a research technologist who is also director of restoration for The American Chestnut Foundation, the group leading the chestnut-restoration effort. “By merging successes in genetic modification, hypovirulence and traditional breeding, restoration of a disease-resistant American chestnut tree is closer.”
The chestnut blight — which wiped out the American chestnut species across its 180-million-acre range in the first half of the 20th century — is caused by a fungus inadvertently introduced from Asia. Some view the loss of the chestnuts, which produced untold tons of food for wildlife and food and lumber for humans, as one of the worst U.S. ecological disasters.