RANDOM-AMPLIFIED POLYMORPHIC DNA (RAPD) ANALYSIS SHOWS INTRASPECIES DIFFERENCES AMONG XANTHOMONAS ALBILINEANS STRAINS

Five strains of Xanthomonas albilineans, causal agent of leaf scald di sease in sugarcane from various geographical regions, were compared us ing random amplification of polymorphic DNA (RAPD) to determine whethe r they could be differentiated at the DNA level. CsCl-purified genomic DNA from these strains were amplified by the polymerase chain reactio n (PCR) using arbitrary 10-mer primers according to standard RAPD cond itions and the amplification product profiles analysed by conventional agarose gel electrophoresis. Although most RAPD markers were common t o all five strains, unique profiles for each strain were discernible u sing four 10-mer arbitrary primers individually. Reproducible DNA fing erprints indicate that RAPD analysis can be used to identify and diffe rentiate the X. albilineans strains. This technique has the potential for use in monitoring the appearance of foreign strains of X. albiline ans in various geographical regions and could be used for the construc tion of phylogenetic trees.