Development of a rapid diagnostic method for Dickeya dadantii, the bacterial canker pathogen of peach, using loop-mediated isothermal amplification.

Abstract

Given that accurate diagnosis of bacterial canker in peach trees that cause rapid death is difficult based on disease symptoms alone, a rapid genetic diagnosis technique is required. In this study, we aimed to develop a rapid and efficient method to identify Dickeya dadantii, the causative agent, using the loop-mediated isothermal amplification (LAMP) method. Two types of DNA were extracted from the thin cambium slices of peach tree trunks and branches. Purified DNA was obtained using a commercial kit. Crude DNA was boiled and diluted with the Tris-HCl buffer. Then, 119 peach tree cambium samples were analyzed to detect D. dadantii using the previously reported polymerase chain reaction method and newly designed LAMP primers. Notably, LAMP exhibited equivalent or superior positivity rates compared to polymerase chain reaction for both DNA types, particularly crude DNA. Additionally, D. dadantii was detected in the resin formed on the peach tree trunks and branches. Overall, the developed method shows potential for the non-invasive diagnosis of infections and mitigation of infection risk for effective fruit tree management.