GENERALIZED TRANSDUCTION IN THE POTATO BLACKLEG PATHOGEN ERWINIA-CAROTOVORA SUBSP ATROSEPTICA BY BACTERIOPHAGE-PHI-M1

Using enrichment methods, a new bacteriophage (phi M1) was isolated, w hich is capable of generalized transduction in Erwinia carotovora subs p. atroseptica (Eca) strain SCRI1043. phi M1 is probably a virulent ph age and contains double-stranded DNA of approximately 43 kb. Transduct ion frequencies for a number of chromosomal markers and plasmid pHCP2 were established, and conditions for transduction optimized. UV irradi ation of the lysates prior to transduction enhanced the transduction f requency. phi M1 infected over 25% of Eca strains tested and so may be useful both for the genetic analysis of a number of Eca isolates and for the transductional transfer of selectable markers between strains.