Abstract:By using SDS-PAGE, the extracellular protein polymorphism of 70 Ralstonia solanacearum wild-type and mutant strains were analyzed. The tested strains possessed abundant variation highly associated with their origins. Twenty protein bands were detected in the EZ-Tn5 TM transponson-generated mutants with a range molecular weights from 20-97 kD, and all mutants shared a highly similar protein band profile. The strains from 60Co-radiated mutagenesis produced 16 protein bands, most of which had molecular weight lower than 44.3 kD. The wild-type strains isolated from diseased plant samples produced the most abundant extracellular proteins (26 bands). Furthermore, extracellular protein concentrations of 37 wild-type R. solanacearum strains with different pathogenicity were determined. The virulent strains produced higher contents of extracellular proteins (1.026 to 5.963μg/mL) than that of avirulent strains (0.083 to 0.761 μg/mL).