Abstract The bacterial pathogen, Xanthomonas campestris pv. citri Group A, causing Oriental canker of Citrus spp., is regarded as a serious microbial threat to New Zealand horticulture. Rapid identification following a breach of biosecurity is essential if eradication is to be achieved. Confirmation of the presence of Oriental canker pathogen can be achieved with a single primer set obtained by DNA subtraction. Primers to X. campestris pv. citri Group B, a pathogen of lesser severity, causing a cankrosis B or false canker, were also developed to discriminate these two pathogens. Specificity of primers for identification of these pathogens was investigated, and the sensitivity of primers for the detection of a specific pathogen in the field was assessed using X. campestris pv. pruni as a surrogate pathogen. The pathogen can be detected from plant tissue without isolating the bacterium by amplifying DNA sequences specific to the pathogen from contaminated tissue washings.
Keywords Citrus canker; identification; quarantine; rep-PCR; DNA subtraction; X. campestris pv. aurantifolii; X. axonopodis pv. citri; X. axonopodis pv. citrumelo; X smithii subsp. citri
New Zealand Journal of Crop and Horticultural Science, 2006, Vol. 34: 195–205
0014–0671/06/3403–0195 © The Royal Society of New Zealand 2006
H05081; Online publication date 6 July 2006. Received 11 July 2005; accepted 11 April 2006
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