Isozyme Analysis as an Indicator of Synonymy of the Causal Agents of Gall Rust on Sand and Virginia Pine. H. R. Powers, Jr., Chief Research Plant Pathologist, USDA Forest Service, Southeastern Forest Experiment Station, Athens, GA 30602. G. Snow, D. Lin, and M. Hubbes. Plant Pathologist, USDA Forest Service, Southern Forest Experiment Station, Gulfport, MS 39503; and Research Associate, and Professor of Forest Pathology, Faculty of Forestry, University of Toronto, Toronto, Ontario, Canada. Plant Dis. 75:1225-1227. Accepted for publication 22 May 1991. 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, 1991. DOI: 10.1094/PD-75-1225.

Isozyme patterns of homogenized aeciospores of Cronartium quercuum from sand pine and Virginia pine were identical and unlike patterns for aeciospores from loblolly, jack, or shortleaf pines, which also differ from each other. These results, together with those of previous inoculation tests, are evidence that strains of C. quercuum from sand and Virginia pine should be assigned the same special form classification, C. quercuum f. sp. virginianae.