Preliminary Study on the Two Different Pathotypes of Ralsionia solanacearum

In order to obtain a reasonable explanation of the phenomenon that there are different virulence between Ralstonia solanacearum typeⅠand typeⅡon the sweetpotato variety Jinshan57, morphological and genome DNA polymorphism were studied in this study.The results were as follows: 1,vaccination results shows jinshan57 high resistance to typeⅠand high sensitive to typeⅡ;2, There was no difference in morphological structure of the two strains based on microscopy and electron microscopy; 3, The DNA which were extracted from the two strains were bacterial 16S rDNA, Polymorphism was found between the two strains by analysis of genome DNA using RAPD markers, and the ratio of polymorphic bands up to 24.04%.The results showed that the genetic diversity maybe contribute to the different virulence between the typeⅠ and typeⅡ strains.