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Etiology

Comparative Growth and Primary Isolation of Spiroplasmas in Media Based on Insect Tissue Culture Formulations. A. L. Jones, Associate Professor, Department of Botany and Plant Pathology, Michigan State University, East Lansing, MI 48824; R. F. Whitcomb(2), D. L. Williamson(3), and M. E. Coan(4). (2)Research Entomologist, U.S. Department of Agriculture, Agricultural Research Service, Plant Protection Institute, Beltsville, MD 20705; (3)Associate Professor, State University of New York, Department of Anatomical Sciences, Stony Brook, NY 11794; (4)Laboratory Technician, U.S. Department of Agriculture, Agricultural Research Service, Plant Protection Institute, Beltsville, MD 20705. Phytopathology 67:738-746. Accepted for publication 29 October 1976. Copyright © 1977 The American Phytopathological Society, 3340 Pilot Knob Road, St. Paul, MN 55121. All rights reserved.. DOI: 10.1094/Phyto-67-738.

The corn stunt organism (CSO) and Spiroplasma citri can be cultivated in a cell-free medium based on Schneider’s medium for cultivation of Drosophila cells. Because Schneider’s medium is largely synthetic, the influence of certain constituent factors on spiroplasma growth could be studied. Growth rates and primary isolation of four CSO strains were deleteriously affected by deletion of organic acids or by reduction of the osmolality of the medium from 540 to 300 mOsm. Inclusion of α-ketoglutaric acid in this medium was especially important for optimal CSO growth. In contrast, the growth rate of four strains of S. citri was reduced markedly by deletion of the defined amino acid constituent, but was not severely reduced by omission of factors that limited CSO growth. Thus, the sufficiency or insufficiency of spiroplasma medium formulations based on insect tissue culture media could be explained in terms of their content of components from Schneider’s Drosophila medium.