DETECTION OF PSEUDOMONAS AVELLANAE FROM HAZELNUT TWIGS BY TAQMAN REALTIME PCR
F. Gervasi, M. Scortichini
A TaqMan real-time PCR assay was developed to detect Pseudomonas avellanae, the causal agent of bacterial canker and decline of hazelnut (Corylus avellana L.). The real-time primers and probe were designed within the 16S rRNA gene of the pathogen after a comparison with other related species and pathovars. The assay detected DNA from a panel of P. avellanae strains obtained from different geographic areas. The other bacterial pathogens inciting diseases to hazelnut, P. syringae pv. coryli, P. s. pv. syringae and Xanthomonas arboricola pv. corylina, did not react in the assay. Only P. s. pv. actinidiae, isolated from kiwifruit and yellow kiwifruit in Italy, cross-reacted. The assay detected the pathogen when inoculated in low numbers (80 cells) in a leaf scar up until nine days after inoculation. The addition of bovine serum albumin was essential to prevent inhibition by compounds released from the hazelnut tissue. This assay could be useful for monitoring the presence of P. avellanae either in orchards or nurseries. Screening for germplasm resistance could also benefit from this technique.