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

Abstract

A non-helical strain of S. 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 1 band was absent. The organism caused symptoms in plants identical to those produced by a pathogenic helical strain of S. citri.