Development of race-specific molecular marker for Xanthomonas campestris pv. campestris race 3, the causal agent of black rot of crucifers

Race-specific molecular markers were established to distinguish Xanthomonas campestris pv. campestris (Xcc) race 3, the causal agent of black rot disease of crucifers. The available genome sequences of Xcc races were aligned and identified three DNA fragments specific to Xcc race 3. The identified race-specific DNA fragments namely XccR3-49, XccR3-52 and XccR3-55 were used for designing the race-specific primers to detect and identify the Xcc race 3. The specificity of race-specific primers was tested against the genomic DNA extracted from Xcc (races 1-7), Xcc strains, Xc pathovars and other bacterial species. The XccR3-49, a specific sequence characterized amplified region (SCAR) primer set gave a single band with 867 bp length for Xcc race 3 only. The remaining two markers such as XccR3-52 and XccR3-55 showed polymorphic amplification with amplicon size of 1889 bp and 2109 bp for Xcc race 3, respectively. Additionally, the SCAR primer set detected Xcc race 3 rapidly and efficiently in artificially infected cabbage leaves with bio-PCR. This result showed that the newly developed race-specific markers can successfully and efficiently detect and identify Xcc race 3 from Xanthomonas campestris pv. campestris races, Xanthomonas species/pathovars, as well as other plant pathogenic bacteria (Pseudomonas syringae pv. maculicola and Erwinia carotovora subsp. carotovora). Up to now, this is the first report describing the race-specific marker for the detection of Xcc race 3.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author