In recent years, the expansion of international seed exports of vegetable crops has led to the spread of both endemic and non-endemic strains of viruses globally. Among these, the Tomato mosaic virus (ToMV) poses a significant threat to the global vegetable industry, particularly the tomato sector, resulting in substantial economic losses. Due to its high pathogenicity and rapid spread, ToMV has been detected in almost all countries, severely impacting the production of tomatoes and other vegetable crops. Rapid and accurate diagnostics of ToMV are crucial for preventing this infectious disease and developing control measures. A practical approach to mitigate ToMV's impact involves the early diagnosis of the virus before plant symptoms appear. This study presents the results of research focused on the preparation of polyclonal antiserum, which is crucial for the immunodiagnostics of ToMV, ensuring high sensitivity and specificity. This modern approach offers high sensitivity, specificity, and rapid results, making it an effective testing system for farmers, researchers, and regulatory bodies in virus detection. The ToMV antigen, purified through physicochemical methods, was administered along with isotonic NaCl solution into the ear vein of an "Albinos" rabbit to produce new polyclonal antiserum. During immunization, the antigen quantity was gradually increased. The antiserum's initial titer was 1:128, which increased to 1:512 after re-immunization. The developed polyclonal antiserum demonstrated high sensitivity in detecting ToMV. It was also applied in the diagnostics of various tomato cultivars infected with ToMV.

Keywords: Tobamovirus, Tomato mosaic virus, Antigen, Polyclonal antiserum, Antibody, Double immunodiffusion