Materials
Sources of blight resistance
¥The old USDA breeding program determined that Chinese chestnut had the most blight resistance of all the chestnut species.  In American forests, the Chinese chestnut itself cannot reach the overstory when competing with other tree species.  We were able to jumpstart our program by using two first backcrosses from the USDA & Connecticut programs.
¥The low levels of blight resistance in some of the large, surviving American chestnut trees might also be useful in a breeding program, which we are exploring.
¥We also use Japanese chestnut as a source of resistance.