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Home → Publications → American Chestnut Proceedings → 1982 → Natural Dissemination of Artificially Inoculated Hypovirulent Strains of Endothia Parasitica

Natural Dissemination of Artificially Inoculated Hypovirulent Strains of Endothia Parasitica

ABSTRACT.--This study was designed to determine if hypovirulent (H) isolates of Endothia parasitica could be recovered from cankers that developed naturally on American chestnuts Castanea dentata previously inoculated with H strains. Isolates from 19 percent (89) of 475 cankers that developed on 220 trees over a 21/2-year period displayed morphological characteristics that were different from wild-type virulent (V) strains. These atypical isolates were separated into six morphological groups. A representative isolate from each group was able to alter the morphology of several V strains when grown together in vitro. Double-stranded RNA was detected in the representative isolates from four of the six groups. The results of these tests and their morphological similarity to known H strains indicate that isolates in at least four of the six groups are H. When cankers that yielded H isolates were extensively sampled, several different H types and V isolates were sometimes recovered from a single infection.


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Author(s): Ronald L. Willey

Publication: American Chestnut Proceedings - 1982