Susceptibility of Flowering Dogwood of Various Provenances to Dogwood Anthracnose. F. S. Santamour, Jr., Research Geneticist, USDA-ARS, U.S. National Arboretum, Washington, DC 20002. A. J. McArdle, and P. V. Strider. Horticulturist, USDA-ARS, U.S. National Arboretum, Washington, DC 20002, and Resource Management Ranger, USDI-NPS, Catoctin Mountain Park, Thurmont, MD 21788. Plant Dis. 73:590-591. Accepted for publication 12 March 1989. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1989. DOI: 10.1094/PD-73-0590.

Seedlings from 20 provenances of flowering dogwood (Cornus florida) showed progressive development of leaf spot and dieback when subjected to natural infection by Discula sp., the causal agent of dogwood anthracnose. Following exposure for two growing seasons, 88 of 120 provenance seedlings (73.3%) were dead, as were 35 of 54 seedlings (64.8%) from intraspecific crosses. Main stems of the remaining seedlings had died back, and the only leaves produced were on epicormic shoots. These results indicate that there may be no host genetic barriers to the continued expansion of the geographic range of the disease. Seedlings of the Chinese dogwood (C. kousa) exhibited leaf spot but no dieback.