Identification of viruses infecting sweet potato in southern China by small RNA deep sequencing and PCR detection

Sweet potato is one of the most important food crops worldwide, and viral diseases can cause very severe yield loss and quality decline of this crop. To track the prevalence of viral diseases of sweet potato in the field, 219 samples were collected from 10 locations in southern China and analysed by small RNA deep sequencing and PCR/RT-PCR. The results showed that 78.54% of the samples were infected with viruses, and 11 virus species were identified. Sweet potato virus G and sweet potato feathery mottle virus had the highest incidence and were detected in more than 40% of the samples that were tested. Coinfection of sweet potato viruses was common in southern China, and 48% of the samples were simultaneously infected by two or more virus species. These results indicate that sweet potato viruses are prevalent in southern China and highlight the importance of accurate diagnostics for their detection and the requirement for the production of virus-free plants.