Development of an identification scheme for the brown rot of potato Ralstonia solanacearum (Smith) Yabuuchi et al. and its validation in a diagnostic laboratory

Relevance. The study is devoted to developing a scheme for the detection and identification of the bacterium Ralstonia solanacearum the causal agent of potato brown rot, which belongs to the Ralstonia solanacearum species complex ( R. solanacearum , R. pseudosolanacearum , R. syzygii ). This pathogen affects over 200 plant species, including economically important crops (potato, tomato, pepper, eggplant), and is listed as a quarantine organism absent from the territory of the Russian Federation. Objective: to create and test a laboratory diagnostic scheme for R. solanacearum for phytosanitary control of regulated products. Material and ". Methods used in the study: sample preparation method (extraction in phosphate-buffered saline with centrifugation), PCR analysis (real-time PCR using primers RS-IF/RS-II-R/RS-P and a commercial kit; PCR with electrophoretic detection using primers RS-1F/RS-1-R (RS-3-R)). Results. An optimized scheme for the identification and detection of the brown rot pathogen was developed. The scheme was tested on 242 samples of regulated products (potato, roses, peonies, bananas) submitted to the diagnostic laboratory in 2025. The results showed the absence of R. solanacearum complex bacteria in samples from the Russian Federation and revealed 14 cases of potato tuber infection in imported batches. Identification of positive samples using species-specific primers RS-1-F/RS-1-R confirmed the presence of R. solanacearum (sensu stricto).

Conclusion. No false-positive or false-negative reactions were recorded during the testing of all used assays within the framework of the developed scheme, indicating their 100% specificity within the study. The outcome of the work is the creation of a reliable laboratory testing algorithm that ensures rapid and accurate diagnosis of the quarantine phytopathogen, thereby guaranteeing phytosanitary safety and compliance of products with importer requirements. plant quarantine, phytopathogenic bacteria, molecular genetic identification methods, detection, identification

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