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Interrelationship between Colony Type, Phage Susceptibility and Virulence in Xanthomonas oryzae
Author(s) -
Goto M.
Publication year - 1972
Publication title -
journal of applied bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 0021-8847
DOI - 10.1111/j.1365-2672.1972.tb03729.x
Subject(s) - virulence , xanthomonas oryzae , mutant , biology , microbiology and biotechnology , bacteriophage , xanthomonas oryzae pv. oryzae , lysogenic cycle , xanthomonas , bacteria , gene , pathogen , genetics , escherichia coli
S ummary : A colonial mutant of Xanthomonas oryzae. (tentatively designated T) had a transparent colony (associated with absence of polysaccharide), resistance to the bacteriophage Bpl and markedly attenuated virulence. Phage resistant mutants with the same colonial characteristics as the wild type (W), which is opaque because of abundant polysaccharides produced, showed various degrees of virulence. Disease symptoms were not suppressed when cells of T were mixed with W in various proportions and used to inoculate rice plants. Disease severity was dependent on the proportion of T in the inoculum and the multiplication of T in the plant was proportional to its initial number of cells in the mixture. When infected rice plants were grown in irrigation water containing phage, little or no selection of phage‐resistant mutants was detected in spite of repeated and high selection pressure. This may be explained by an insufficient supply of bacterial cells from diseased leaves into the irrigation water and by the very low propotion of phage‐resistant mutants that are virulent.