Highly sensitive reverse transcription loop-mediated isothermal amplification for detecting and identifying groundnut ringspot and tomato spotted wilt orthotospoviruses

Abstract

Orthotospovirus arachianuli (groundnut ringspot virus, GRSV) and Orthotospovirus tomatomaculae (tomato spotted wilt virus, TSWV) represent a threat to several agricultural crops worldwide. The management of the diseases they cause is particularly challenging due to their wide host range and transmission by thrips vectors. Accurate diagnosis and early detection are crucial, especially considering the limitations of conventional serological and molecular methods. This study introduces reverse transcription loop-mediated isothermal amplification (RT-LAMP) as a reliable alternative for detecting and identifying GRSV and TSWV in tomato, pepper, and peanut plants. The designed primer sets specifically targeted and amplified fragments of the viral RNA S segment. RT-LAMP reactions produced negative results in the healthy plants and exhibited no cross-reactivity with closely related orthotospoviruses or viruses from other genera. Compared to RT-PCR, RT-LAMP exhibited superior sensitivity, detecting viral RNA at concentrations 100 times lower. Field testing on symptomatic plants further confirmed the effectiveness of this technique. Overall, this study highlights RT-LAMP as a rapid, species-specific, and highly sensitive tool for the early detection of GRSV and TSWV in economically important crops, offering a promising solution for improved disease management.