Molecular Characterization of Tobacco Rattle Virus (TRV) Isolates and Their Nematode Vector Relationships in Potato Fields

Abstract

Potato is an important food crop worldwide, but its production is significantly affected by viral diseases that reduce yield and tuber quality. Tobacco Rattle Virus (TRV), a member of the genus Tobravirus, is an economically important pathogen associated with spraing disease in potato, characterized by necrotic arcs, rings, and internal browning of tubers. The transmission of TRV is primarily mediated by soil-dwelling nematodes, making its epidemiology complex and difficult to manage. The present study was conducted to characterize TRV isolates and investigate their relationships with nematode vectors in potato fields. Field surveys were carried out in major potato-growing regions, and symptomatic tubers and plants showing typical spraing symptoms were collected for analysis. Total RNA was extracted from infected samples and subjected to reverse transcription polymerase chain reaction (RT-PCR) using TRV-specific primers targeting conserved genomic regions. Amplified products were sequenced and analyzed to determine molecular variability and phylogenetic relationships among isolates. In parallel, soil samples were collected to identify and quantify nematode species associated with infected fields, and their association with TRV presence was assessed. The results confirmed the widespread occurrence of TRV in symptomatic potato plants, while healthy samples tested negative. Molecular analysis revealed genetic diversity among TRV isolates, with phylogenetic clustering indicating both local adaptation and similarity to globally reported strains. Nematode assessment identified specific vector species strongly associated with TRV-infected fields, suggesting their critical role in virus transmission and disease spread. The study highlights the complex interaction between TRV isolates and their nematode vectors in potato agroecosystems. These findings emphasize the importance of integrated management strategies combining virus-free planting material, vector control, and regular monitoring to reduce disease incidence and minimize economic losses in potato production systems.