Rapid and sensitive detection of Pseudomonas syringae pv. actinidiae causing bacterial canker of kiwifruit using recombinase‐aided amplification with lateral flow dipstick assay

Abstract Bacterial canker of kiwifruit, caused by Pseudomonas syringae pv. actinidiae (Psa), is a highly destructive disease that results in significant economic losses. Timely detection of Psa is essential for implementing effective disease control measures. In this study, a recombinase‐aided amplification with lateral flow dipstick (RAA‐LFD) assay targeting the type III effector avirulence D1 ( AvrD1 ) gene was developed. The assay was optimized for reaction conditions to ensure a swift and accurate detection protocol suitable for field application. In tandem, conventional PCR was also selected for comparison with the RAA‐LFD assay. The RAA‐LFD assay demonstrated a detection limit of 1 pg/μL for genomic DNA and 10 4 cfu/mL cell suspension. Specificity testing confirmed that the assay exclusively targeted Psa without cross‐reactivity with other endophytic bacteria present in kiwifruit. To validate the RAA‐LFD assay, it was compared with the conventional PCR method using 56 field samples. The results from both methods were found to be in complete agreement, validating the RAA‐LFD as a reliable diagnostic tool. Therefore, the established Psa RAA‐LFD assay provided technical support for the early and accurate diagnosis of bacterial canker in kiwifruit, which is crucial for disease management and prevention strategies.