Lost chestnut set for genetic revival

摘要

The near-extinct American chestnut looks set to make a comeback. Trees genetically modified to survive a deadly fungus have made the first seeds with resistant genes. From these, countless resistant trees could grow in the wild. Biotechnology could save its first species. About 4 billion American chestnut trees (Castanea dentata) once covered the US, accounting for a quarter of all hardwood trees in the country. But around 1900 a lethal fungus was inadvertently imported in chestnut trees from Asia. By the 1950s, Cryphonectria parasitica had almost completely wiped out the native tree. The American Chestnut Research and Restoration Project has spent 20 years trying to save the species. Led by William Powell and Charles Maynard of the State University of New York in Syracuse, the team has genetically modified trees to resist the fungus. It is the only conservation project to use biotechnology.