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Submitted to: American Phytopathological Society
Publication Type: Abstract Only Publication Acceptance Date: 6/2/1997 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Progress in phytoplasma classification is unveiling a remarkably wide breadth of diversity among phytoplasmas. It is now widely appreciated that very similar symptoms may be induced in a given plant species by taxonomically distinct phytoplasmas that represent different "Candidatus Phytoplasma species". In some instances, what was once thought to be a single disease has been revealed as a complex of several diseases - each associated with a distinct phytoplasmal pathogen. Molecular detection and identification of phytoplasmas have provided evidence that grapevine yellows, for example, comprises several distinct diseases in which a similar syndrome is induced by several distinct phytoplasma species. In other cases, strains of the same phytoplasma species may induce distinctly different symptoms in a given host; such is not uncommonly seen in phytoplasma strain collections maintained by experimental grafting in periwinkle (Catharanthus roseus). These observations pose significant scientific enigmas, provoking questions both about the mechanisms whereby phytoplasmas elicit disease symptoms in plants and about the repertoire of potential responses of a plant species to phytoplasmal pathogenesis. In the practice of plant pathology in the field, they underscore the importance of correct phytoplasma identification in disease diagnosis and treatment. |
