Random-amplified polymorphic DNA (RAPD) analysis shows intraspecies differences among Xanthomonas albilineans strains

Five strains of Xanthomonas albilineans, causal agent of leaf scald disease in sugarcane from various geographical regions, were compared using random amplification of polymorphic DNA (RAPD) to determine whether they could be differentiated at the DNA level. CsCl-purified genomic DNA from these strains were amplified by the polymerase chain reaction (PCR) using arbitrary 10-mer primers according to standard RAPD conditions and the amplification product profiles analysed by conventional agarose gel electrophoresis. Although most RAPD markers were common to all five strains, unique profiles for each strain were discernible using four 10-mer arbitrary primers individually. Reproducible DNA fingerprints indicate that RAPD analysis can be used to identify and differentiate the X. albilineans strains. This technique has the potential for use in monitoring the appearance of foreign strains of X. albilineans in various geographical regions and could be used for the construction of phylogenetic trees.