Can fungal endophytes protect American Chestnut (Castanea dentata) from blight (Cryphonectria parasitica)?

The virulence of each C. parasitica strain was characterized with the Golden Delicious apple assay.  Pathogenicity tests using Golden Delicious apples have been shown to correlate with in planta tests using chestnut stem sections or living trees. Fifteen, fresh, unblemished Golden Delicious apples were wiped clean with 100% ethanol and inoculated at equidistance with each of the four, hypovirus-free C. parasitica test strains used in the current study.  In addition, 5 apples were inoculated with a confirmed, hypovirus-infected C. parasitica as well as an uncharacterized lab strain (two inoculations of each isolate in each apple).