ABSTRACT The new primers were developed for specific detection of Xanthomonas citri subsp. citri (Hasse) (Xcc) [syn. X. axonopodis pv. citri (Xac)], the causal agent of Asiatic citrus canker disease. Twenty three strains of Xcc and 34 strains of other xanthomonads including X. fuscans subsp. aurantifolii, X. alfalfae subsp. citrumelonis, X. campestris pv. campestris, X. campestris pv. glycines, X. citri subsp. malvacearum and X. fuscans subsp. fuscans were tested for specificity of new primers by classical PCR. The results showed that these 354 F/R primers specifically amplified all of Xcc strains but not other xanthomonad strains. The 354-bp PCR fragment was sequenced and its nucleotide sequences were compared for similarity with Genbank database. The 354-bp nucleotide sequences were 99.7% similar to gene XAC2443 of Xac strain 306 (Accession AE011881). The sensitivity of these specific primers for detection of viable cells and total DNA of Xcc were 70 CFU/µl and 50 pg/µl, respectively. Therefore, these novel primers can be used as an alternative application for rapid and specific detection of Xcc
