Diagnostiek van Xanthomonas arboricola (BO-33.03-001-003)

Development of TaqMan PCR using an unique target genomic sequence of XAP

In the Netherlands, until now, only P. laurocerasus (ornammental cherry) has found to be infected; the first report of infected plants date from 2009. Several look-a-likes were found (personal communication Naktuinbouw; EJPP 2012) which gave false-positive signals in the exsisting TaqMan PCR test (Palacio-Bielsa et al. 2012). Being a quarantine disease, the NVWA, Inspection Service as well as the growers need a validated and specific diagnostic test.   This real time PCR is based upon an unique target chromosomal  of XAP as assessed by genomic analysis and comparison with closely related X. arboricola pathovars; an internal PCR control (Cytochrome oxidase I gene) will be added to the assay.   Objectives: - Analysis of the available identification- and detection assays, based upon DNA targets for XAP in close collaboration with COST873 and Euphresco II partners. - The development and validation of a multiplex TaqMan PCR with at least one of the targets localized on the chromosome of XAP. - Evaluation of the developed TaqMan with partners (Nvwa, Naktuinbouw).   Result A Taqman-test has been developed and tested. Validation revealed that specificity was hampered due to so called look-a-likes. The problems of these look-a-likes are subject to further research (i.e. Euphresco and EU-DROPSA).