Sweetpotato viruses in China

China is the largest sweetpotato producer country in the world, with its total growing area and yield reaching 5.5 million ha and 106 million metric tones, respectively. Viral diseases constitute a major hindrance to the development and highly profitable production of the sweetpotato industry. The present article provides updated comprehensive information on type of virus, yield loss caused by viruses, increased yield and benefits by cultivation of virus-free plants. By analyzing data on changes in vegetative growth and physiology of plants infected by viruses, the authors attempted to elucidate the mechanisms by which infection of viruses caused significant losses of the root tuber yield. Meristem culture techniques for production of virus-free sweetpotato plants and propagation system of virus-free seed tubers have been well developed in China. At present time, virus-free sweetpotato seed tubers have been widely used in major sweetpotato-growing areas in China. Usage of virus-free seed tubers has brought great benefits to the sweetpotato industry in China.