VIEW ARTICLE

Physiology and Biochemistry

Revised Estimates of the Molecular Weights of dsRNA Segments in Hypovirulent Strains of Endothia parasitica. J. A. Dodds, Department of Plant Pathology, The Connecticut Agricultural Experiment Station, P. O. Box 1106, New Haven, 06504; Phytopathology 70:1217-1220. Accepted for publication 9 June 1980. Copyright 1980 The American Phytopathological Society. DOI: 10.1094/Phyto-70-1217.

Multisegment dsRNAs were detected by polyacrylamide gel electro-phoresis of preparations purified by CF-11 cellulose chromatography from twelve hypovirulent strains of Endothia parasitica isolated from France, Italy, and North America. Ethidium bromide-stained dsRNA segments were identified by incubating individual gels with ribonuclease, first in 0.3 NaCl and then in water. The molecular weights of the dsRNA segments were between 4.0 and 7.0 × 10⁶. The types of dsRNA in European strains (type 1 in one strain, type 2 in seven strains) were distinct from each other and from the dsRNAs in North American strains (type 3 in four strains). Levels of pathogenicity or growth rate were not correlated with types of dsRNA. The concentration of dsRNA was lower in North American strains than in European strains.