Taxonomic note on Cronartium quercuum
In the USA, experiments were carried out to compare strains of Cronartium quercuum (EPPO A1 organism) collected from sand pine (Pinus clausa) with C. quercuum f.sp. virginianae obtained from Virginia pine (Pinus virginiana).
The isozyme patterns of homogenized aeciospores showed that C. quercuum from sand pine and C. quercuum f.sp. virginianae from Virginia pine are identical and, therefore, should both be classified as Cronartium quercuum f. sp. virginianae.
Sources
Powers, H.R., Jr.; Snow, G.; Lin, D.; Hubbes, M. (1991) Isozyme analysis as an indicator of synonymy of the causal agents of gall rust on sand and Virginia pine.
Plant Disease 75, 1225-1227.