Development of the Droplet Digital PCR Method for the Detection and Quantification of Erwinia pyrifoliae

Abstract

Black shoot blight disease caused by <i>Erwinia pyrifoliae</i> has serious impacts on quality and yield in pear production in Korea; therefore, rapid and accurate methods for its detection are needed. However, traditional detection methods require a great deal of time and fail to achieve absolute quantification. In the present study, we developed a droplet digital polymerase chain reaction (ddPCR) method for the detection and absolute quantification of <i>E. pyrifoliae</i> using a pair of species-specific primers. The detection range was 10³ - 10⁷ copies/ml (DNA templates) and cfu/ml (cell culture templates). This new method exhibited good linearity and repeatability and was validated by absolute quantification of <i>E. pyrifoliae</i> DNA copies from samples of artificially inoculated immature pear fruits. Here, we present the first study of ddPCR assay for the detection and quantification of <i>E. pyrifoliae</i>. This method has potential applications in epidemiology and for the early prediction of black shoot blight outbreaks.