Development of a quantitative qPCR assay for the detection of Pseudomonas avellanae in hazelnut tissues

Abstract

Corylus avellana L. (hazelnut) is a shrub species threatened by several bacterial and fungal pathogens and a fast and reliable diagnostic method is necessary to discriminate among them. In this study, we applied a pangenomic approach to develop a specific qPCR assay BRYT Green® dye-based for the specific detection of Pseudomonas avellanae, the causal agent of the bacterial canker and hazelnut decline, among the numerous pseudomonads colonizing hazelnut tissues. Specific PCR primers were designed on the candidate regions identified as single core regions of P. avellanae and their specificity was tested on a large range of Pseudomonas spp., on other hazelnut bacterial pathogens, as well as on endophytic bacteria isolated from hazelnut leaves. This new qPCR assay constitutes a sensitive tool for the detection and quantification of P. avellanae in field samples that can play a key role in the early diagnosis and prevention of the bacterial canker and decline of hazelnut.