Imagine chestnut trees 17 feet in diameter and towering more than 100 feet tall, like green skyscrapers in the forest. It must have been quite a sight to behold. Those majestic trees are now considered functionally extinct as a result of an introduced fungal pathogen that piggybacked on Asian chestnut shipped into North America in the late 1800s. The American chestnut had no resistance and the disease spread quickly, creating a massive trail of dead trees in the eastern U.S. By 1950, the fungus had eliminated American chestnut as a mature forest tree.
The American Chestnut Foundation (TACF) is a nonprofit conservation, education, and scientific organization with one of the most ambitious rescue missions in the natural world–to save a beloved tree species from extinction. Founded in 1983 and based in Asheville, NC, TACF and its 16 state chapters are working to restore the American chestnut tree to eastern forests. We employ breeding, biotechnology, and biocontrol to develop a blight-resistant American chestnut tree in order to save the species and return it to its native range which stretches from Maine to Alabama. We are supported by private individuals and family foundations, and the majority of our work is done by thousands of dedicated citizen scientists and partners.
The scientists who founded TACF were interested in testing a breeding method proposed by retired crop geneticist Dr. Charles Burnham. He hypothesized that the backcross breeding methods he used in corn might also work on chestnuts if only two or three genes were responsible for resistance to the blight fungus exhibited by Chinese chestnut trees.
Burnham and TACF’s first president Phillip Rutter joined forces with researchers from several universities and with individuals interested in returning the American chestnut to its former prominence. They fully understood the severe impacts the demise of the tree imposed on the economies of rural communities and upon the ecology of forests within the chestnut’s native range.
In 1989, TACF established the Wagner Research Farm in Meadowview, Virginia, to carry out Burnham’s backcross strategy. Mary Belle Price donated a second research farm to the Foundation in 1995, in memory of her late husband, Glenn C. Price, a strong supporter of TACF. Two additional Meadowview farm plots were purchased in 2002 and 2006, respectively.
Two independent reviews of TACF’s scientific mission, methods, and results were conducted in 1999 and 2006, by prominent scientists from around the world. Those reviews contributed significantly toward guiding the direction of the breeding program. With recent developments in genomic technology, TACF recognized the need for a new review. In 2018, TACF hosted a panel of five senior scientists with expertise in tree improvement and forest genetics in Abingdon, Virginia. Over a two-day period, they attended presentations and field trips in the nearby Meadowview breeding and testing facilities. The review panel was impressed by the work, in-depth self-analysis, and planning presented by TACF staff.
Through decades of backcrossing and, now, integration of genomic analysis, we have learned that blight resistance is a complex trait controlled by many genes. Today, TACF takes a holistic approach, utilizing a three-pronged research strategy we call 3BUR (Breeding, Biotechnology, and Biocontrol United for Restoration). These research tracks are meant to be integrated through collaborations that are mutually beneficial, so we can explore all avenues to reach the common goal of saving and restoring the American chestnut as quickly as possible.
Restoration of this invaluable tree to its former native range in the Appalachian hardwood forest is a major project that requires a multi-faceted effort involving members, volunteers, state chapters, scientists, sustained funding, and, most importantly a sense of the past and hope for the future.