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Etiology

Erwinia chrysanthemi: Serological Relationships Among Strains from Several Hosts. Robert S. Dickey, Professor, Department of Plant Pathology, Cornell University, Ithaca, NY 14853; Cathy H. Zumoff(2), and Jerry K. Uyemoto(3). (2)Research technician, Department of Plant Pathology, Cornell University, Ithaca, NY 14853; (3)Associate professor, Department of Plant Pathology, New York State Agricultural Experiment Station, Cornell University, Geneva 14456, Current address: Department of Plant Pathology, Kansas State University, Manhattan 66506. Phytopathology 74:1388-1394. Accepted for publication 11 June 1984. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/Phyto-74-1388.

Nine antisera were produced against formalin-treated strains of Erwinia chrysanthemi, and four serovars were distinguished that were designated serovars I, II, III, and IV. Antisera produced to five strains originally isolated from three hosts (sedum, carnation, or philodendron) from different geographical locations were similar when tested by Ouchterlony double diffusion for reaction of identity (serovar I); the two strains from Musa paradisiaca produced similar antisera (serovar IV). Three hundred and fifteen (78%) of 404 strains of E. chrysanthemi originally isolated from 42 hosts reacted with one or more of the nine antisera, whereas none of the 103 strains of other Erwinia species or subspecies reacted with any of the antisera. All strains isolated from 25 of 42 hosts reacted only with the antisera of serovar I, and all strains from Musa paradisiaca reacted only with antisera of serovar IV. None of the strains isolated from seven hosts reacted with any of the antisera; some strains from each of the nine remaining hosts reacted with one or more antisera, whereas other strains from the same host did not react with any of the antisera. There was no correlation between reaction to antisera and assignment of strains to five of the six previously described phenotypic subdivisions. Ninety strains of E. chrysanthemi (serovar I) from 34 plant species, subspecies, or cultivars were tested for agglutination with unabsorbed antiserum produced against a strain isolated from Dianthus caryophyllus and with antisera absorbed with a strain from Dieffenbachia amoena or from Saintpaulia ionantha. Three kinds of reactions to the absorbed antisera were observed; however, a definite relationship between original host or phenotypic properties and reaction to absorbed antisera was not demonstrated.