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Abstract
More than 100 isolates of the chestnut blight fungus, Cryphonectria parasitica (=Endothia parasitica), were collected during a survey across Pennsylvania from infected scarlet oaks (Quercus coccinea) suffering from basal Cryphonectria cankers. Comparisons were made among isolates, as well as to a standard virulent (relative to American chestnut) and standard hypovirulent isolate in terms of linear growth on agar, lesion area induced in apple fruit, and canker area induced on American chestnut saplings. A ranking test indicated that growth on agar, lesion area induced in apple, and canker size induced on American chestnut were correlated. Most isolates grew on agar, infected apple fruit, and infected chestnut stems in a manner similar to that of the standard virulent isolate. A reservoir of virulent inoculum from scarlet oaks may confound efforts at biological control of chestnut blight on American chestnut. The possibility that a small number of isolates from scarlet oak may be hypovirulent on American chestnut should be investigated because one isolate had characteristics similar to the known hypovirulent isolate.
Parent Publication
Citation
Davis, D.D.; Torsello, M.L. 1999. Characteristics of the chestnut blight fungus isolated from scarlet oak in Pennsylvania. In: Stringer, Jeffrey W.; Loftis, David L., eds. 1999. Proceedings, 12th central hardwood forest conference; 1999 February 28-March 1-2; Lexington, KY. Gen. Tech. Rep. SRS-24. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station. 293 p
