¥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 canopy 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.
¥Additionally, we use Japanese chestnut as a source of resistance.