MUTATION CONFERRING STREPTOMYCIN RESISTANCE IN XANTHOMONAS PHASEOLI

Spontaneous mutations conferring resistance to the action of 500 to 2000 μg/ml streptomycin occur at an over-all rate of about 3 × 10−10per bacterium per generation in Xanthomonas phaseoli. Some mutants will not grow in the absence of streptomycin; others grow both in the presence and in the absence of the drug. In most cases resistance to high concentrations of streptomycin does not affect the virulence of this organism for bean plants.