Hopes for Chestnut Revival Growing
Scientists are on the brink of engineering a blight-resistant American chestnut tree, renewing hope for a comeback of a long-celebrated species that is valued by business for its sturdy hardwood.
For the first time, techniques used to genetically engineer sturdier farm crops are being tapped to bring back a devastated native species—one that once numbered in the billions and covered much of the East Coast. Now, chestnut trees whose lives began as smudges on a Petri dish are growing in upstate New York, their genes infused with a wheat DNA that appears to kill the fungus that attacks the tree's trunk and limbs. Unlike chestnuts in nature, these trees haven't succumbed so far to the blight—even when scientists directly infect them with it.
Attempts to restore the American chestnut began in the 1930s, when scientists unsuccessfully tried to breed the tree with a Chinese variety that was immune to the fungus. Federal funding dried up by the 1960s.
The efforts were picked up again in the 1980s by scientists and plant lovers who founded the American Chestnut Foundation. They applied a new method, called backcross breeding, which was first used for corn that imparts preferable traits over several generations.
Meanwhile, scientists at Syracuse's forestry college began experimenting in 1990 with a technique called transgenics, which was traditionally used to create genetically modified crops. They inserted a fungus-resistant wheat gene into an American chestnut embryo and grew a tree from a single cell in a Petri dish.
Returning the chestnut to American forests in large numbers could depend on help from the mining and timber industry. Federal law requires mining companies to restore land they strip through means that include forestation. Chestnuts thrive in the loose, sandy soils left after mining.