Today, April 25, 2014 is National Arbor Day and a reminder of the importance that individuals and groups need to plant and care for trees. This means ensuring that arboriculturists and foresters have access to the most up to date agricultural technologies. The American Chestnut blight is recent example of how genetic engineering has served as one of these vital technologies.
A recent piece published in Scientific American told of the blight of the American Chestnut – nearly wiped out by a fungal disease– and efforts to genetically engineer the trees to resist the fungus and reintroduce healthy trees back into America forests. Ferri Jabr’s A New Generation of American Chestnut Trees May Redefine America’s Forests examines the history of the American Chestnut going from its role of providing food and shelter for animals and people to nearly becoming obsolete.
“Before the early 1900s, one in every four hardwood trees in North America’s eastern forests was an American chestnut, providing copious food and shelter for animals and people alike….
“A New York City nurseryman named S. B. Parsons imported Japanese chestnut trees in 1876, which he raised and sold to customers who wanted something a little exotic in their gardens. Other nurseries in New Jersey and California soon did the same.
“One or perhaps all of these shipments concealed the pathogenic fungus Cryphonectria parasitica, which chokes chestnut trees to death by wedging itself into their trunks and obstructing conduits for water and nutrients. Asian chestnut trees had long evolved resistance to C. parasitica, but their American relatives—which had never encountered the pathogen before—were extremely susceptible to the fungal disease known as chestnut blight.”
In 1904 the fungus was first discovered in New York State and soon spread to New Jersey, Connecticut, Massachusetts and Pennsylvania. Within 50 years, C. parasitica killed nearly four billion chestnut trees.
“Since the 1980s several generations of researchers at the State University of New York College of Environmental Science and Forestry (S.U.N.Y.–ESF) have toiled to restore the American chestnut to its native habitat. Genetic engineering has offered a successful route to restoration.
“By taking genes from wheat, Asian chestnuts, grapes, peppers and other plants and inserting them into American chestnut trees, William Powell of S.U.N.Y.–ESF and scores of collaborators have created hundreds of transgenic trees that are almost 100 percent genetically identical wild American chestnut yet immune to C. parasitica.”
The scientists hope to get federal approval to begin planting these trees in the forest within the next five years (See “The American Chestnut’s Genetic Rebirth” in the March 2014 issue of Scientific American).