American chestnut restoration©
Breeding American chestnuts for resistance to chestnut blight has been on-going in some capacity since the early twentieth century. Early efforts focused on hybridizing American chestnut with Chinese chestnut (Castanea mollissima) and Japanese chestnut (Castanea crenata), in order to capture the pathogen resistance of these Asian species. The breeding program of The American Chestnut Foundation was developed utilizing some of the lessons learned by early breeders, and built upon earlier efforts. TACFs program utilizes an initial hybrid cross to Chinese chestnut in order to capture blight-resistance, several successive backcrosses to American chestnuts to increase the representation of the American species, as well as the genetic diversity of the breeding population, and a series of intercrosses to bolster resistance further. This program is currently at a point where we can evaluate its efficacy to-date, and determine what kinds of adjustments could be made to improve blight resistance further.
Collins, K., Fitzsimmons, S., Saielli, T. and Westbrook, J. (2017). American chestnut restoration©. Acta Hortic. 1174, 215-218