Journal of Plant Pathology (2007) 89, S35-S36

A. Chimento, S.O. Cacciola and M. Garbelotto (2007)
Reverse-transcription real-time PCR assay to detect viable propagules of Phytophthora ramorum in infected plant tissues
Journal of Plant Pathology 89 (3, Suppl.), S35-S36
Poster Presentation at S.I.Pa.V XIV National Meeting - Perugia, Italy 19-21 Sept. 2007
Abstract: A new reverse-transcription real-time PCR (RT-PCR) assay was developded, based on the use of mRNA as a marker to detect viable propagules of Phytophthora ramorum Werres, De Cock and Man in't Veld. This method is based on the rapid degradation of mRNA compared to DNA. New primers specific for P. ramorum were designed in the cytochrome oxidase gene encoding subunits I (COXI). To evaluate the specificity of the method, four isolates of P. ramorum and reference isolates of eleven different Phytophthora species were tested. Sixty leaves of Californian bay laurel [Umbellularia californica (Hook. and Arn.) Nutt.] with symptoms of sudden oak death disease from three different sites in California (USA) and sixty symptomatic leaves of Californian bay laurel collected in three different seasons of the year from China Camp State Park (CA) were plated on PARP selective medium and tested with the RT-PCR assay in comparison with a TaqMan and a SybrGreen Real-Time PCR assay, after a classical DNA extraction. Results showed that after nine days RNA of P. ramorum killed by freeze-drying was undetectable while DNA gave a positive signal. Furthermore, differently from method based on DNA analysis, the results of the RT-PCR assay were correlated with positive isolations on selective media, thus indicating that the risk of PCR false positives can be circumvented by using this RT-PCR method.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Santa O. Cacciola

Research topic(s) for pests/diseases/weeds:
identification/taxonomy
surveys/sampling/distribution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Phytophthora ramorum	Umbellularia californica (crop)	U.S.A. (SW)