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Genetics

Molecular Relatedness Among Cryptic Plasmids in Pseudomonas syringae pv. glycinea. Michael S. Curiale, Former graduate student Genetics Program, Genetics Program and Department of Botany and Plant Pathology, Oregon State University, Corvallis 97331, Present address of senior author: Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA 02111; Dallice Mills, associate professor, Genetics Program and Department of Botany and Plant Pathology, Oregon State University, Corvallis 97331. Phytopathology 73:1440-1444. Accepted for publication 18 May 1983. Copyright 1983 The American Phytopathological Society. DOI: 10.1094/Phyto-73-1440.

Molecular homology was detected among the plasmids harbored by six pathogenic strains of Pseudomonas syringae pv. glycinea. By using the Southern blot technique, radioactive plasmid DNA probe prepared from strain LR 100 hybridized to 55- 75% of the EcoR1-generated fragments of the other five strains. The reciprocal reaction was performed between membrane-bound EcoR1-digested LR100 plasmid DNA and plasmid probe prepared from four of the other strains. Each of these probes hybridized to three specific EcoR1 fragments from plasmid pMC11 and one fragment from plasmid pMC10. From one to nine other bands showed homology with specific probes. This interrelationship among the plasmids was not detected by visual examination of the EcoR1 fingerprints, although similarities between the restriction patterns of some plasmids were clearly evident.