In today’s Academic Minute, Dr. William Powell of the State University of New York’s College of Environmental Science and Forestry explains how genetic modification can save trees from blight.
William Powell is a professor of environmental and forest biology at the State University of New York’s College of Environmental Science and Forestry. His research is focused on restoring the American Chestnut tree through finding ways to combat the century-long blight, Cryphonectria parasitica. He earned his Ph.D. at Utah State University.
Dr. William Powell – Blight Resistant Trees
Our forests, and trees in general, are under attack by exotic pests and pathogens. They make up an impressive list: hemlock wooly adelgid, dogwood anthracnose, walnut thousand canker disease, sudden oak death, butternut canker, beech-bark disease and ash trees to the emerald ash borer. Recently, citrus greening on orange trees has become so severe it might soon be the end to inexpensive orange juice.
These new environmental plagues in many ways mirror what happened to the American chestnut tree.
What lessons have been learned that might help us today? First, just as with human health, prevention is the best remedy but, even with the best measures, sometimes pests and pathogens slip in. Containment and eradication is the next defense although this usually only works early on. Too often, once a pest or pathogen is discovered in an area, it has already spread extensively so the only thing we can do is to adapt. Adapting includes control measures, such as pesticides and horticultural practices, and/or developing resistant trees.
While breeding trees with similar but resistant species is the traditional method, the approach we’ve taken with chestnut is to use modern biotechnology techniques to add just two to four genes to enhance blight resistance so the tree will retain all the desirable traits of a typical American chestnut tree, such as its majestic height and girth but, also be able to survive the blight.
It has taken 23 years of research but we have found a gene from bread wheat that detoxifies an acid used by the blight fungus to infect the tree. Field trials are underway and we’re very close to beginning the restoration of the American chestnut to the forest. But we must be patient as an old Chinese proverb advises, "One generation plants the tree, the next generation enjoys the shade."