Isolation and Characterization of a Non-Helical Strain of Spiroplasma citri

SUMMARY: A non-helical strain of Spiroplasma citri from little-leaf diseased oranges was subcultured over 40 times in different media without producing helical cells. It was non-motile and produced colonies of a characteristic morphology on soft agar plates. Serology, DNA hybridization and toxin production confirmed that it was a strain of S. citri but its membrane protein pattern after polyacrylamide gel electrophoresis differed from those of other S. citri strains in that one band was absent. The organism caused symptoms in plants identical to those produced by a pathogenic helical strain of S. citri.