M.T. Alexander, L.M. Worthen, J.H. Craddock
The ongoing effort to breed and reintroduce a blight resistant, locally adapted variety of American chestnut (Castanea dentata) requires a broad genetic base. To ensure adequate genetic diversity, we have collected genetic resources from across the southeastern portion of the native range of the species. Finding and breeding surviving C. dentata stump sprouts is problematic due to the relatively short life span of blooming stems and their often remote forest habitat. We implemented a combination of conservation procedures including both in situ efforts to promote favorable habitat conditions for survivors, and ex situ techniques such as traditional breeding, grafting, and orchard repositories. To facilitate more efficient location of surviving trees we employed the use of a Geographic Information System (GIS) to overlay soil, topography, and satellite imagery for the generation of predictive, site-specific, chestnut-range maps, as well as a geo-referenced attribute database. In 2002 our efforts resulted in the location of three surviving, seed-bearing, American chestnut trees in Tennessee. We bred the wild trees using C. dentata and hybrid pollens resulting in the capture of native germplasm into our breeding program. In 2003 we located and bred an additional 5 wild trees. In 2004 a record number of 12 wild trees were pollinated in Tennessee. In 2004 we located and graft-propagated 18 different C. dentata trees for inclusion in the breeding orchards.
Alexander, M.T., Worthen, L.M. and Craddock, J.H. (2005). CONSERVATION OF CASTANEA DENTATA GERMPLASM OF THE SOUTHEASTERN UNITED STATES. Acta Hortic. 693, 485-490
DOI: 10.17660/ActaHortic.2005.693.62
American chestnut, forest species restoration, backcross breeding, GIS, gene conservation

Acta Horticulturae