Starting in 1900 a blight fungus spread through all American Chestnut forests, wiping out almost all American chestnuts by 1940. A New York Times article reports on two groups that have developed American chestnut strains that have resistance to the blight. One strain was made by crossing with a Chinese chestnut and another was made by genetic engineering.
I am especially hoping the genetically engineered strain succeeds because it has the smallest genetic difference with regular American chestnut. But likely either would be a boon.
Over 100 years ago chestnut represented about 25% of the trees in the American east. A revival of American chestnut would be a boon fora number of wild animal populations that can live off the seed crop.
Most trees produce a seed crop every three to four years through a process called masting, but the American chestnut produces a crop every year, which makes them a very important and consistent food for wildlife. The chestnut's plentiful seeds can also provide nutrition for animals. According to McCarthy, the trees were once the premiere food source of all major vertebrates in Appalachian Ohio forests. The blight, along with subsequent over hunting and the loss of habitat, caused deer, turkey and squirrel populations to plummet in Ohio forests by the 1930s.
The backcrossing method of breeding with Chinese trees is being done in a way that gets a lot of the diversity in existing American chestnuts. That makes them more resistant to other threats and gives them genetic features that adapt them to local conditions.
|Share |||Randall Parker, 2013 July 14 08:40 PM|