Determination of Beet Necrotic Yellow Vein Virus Infection from Spinach Fields of South Marmara Region in Türkiye

Spinach (Spinacia oleracea L.) is a major winter vegetable, produced and consumed in large quantities both globally and in Türkiye. Its cultivation faces significant economic losses due to various fungal, bacterial, and viral diseases, with viral infections being particularly critical due to the lack of effective chemical control measures. One of the major viral threats to spinach is Benyvirus necrobetae (beet necrotic yellow vein virus; BNYVV), the causal agent of "Rhizomania" disease. Although the presence of BNYVV has been documented in several production regions in Türkiye, its status in the spinach-growing areas of Bursa and Balıkesir provinces remains unclear. To address this gap, field surveys were conducted, and 83 spinach plants showing virus-like symptoms were sampled from the Southern Marmara provinces of Çanakkale, Balıkesir, and Bursa. The samples were tested for BNYVV using double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) with BNYVV-specific antisera. The serological results were further validated by reverse-transcription polymerase chain reaction (RT-PCR) using BNYVV-specific primers. The findings confirmed the presence of BNYVV in all sampled provinces, with 26 out of 83 samples testing positive, indicating an infection rate of 31.32%. These results suggest that BNYVV infection is widespread in spinach cultivation areas of the Southern Marmara Region. Future research should focus on identifying virus isolates at the pathotype level and exploring their interactions with the fungal vector Polymyxa betae (Keskin).