Watermelon (Citrullus lanatus) is an important crop in China with the largest planted countries in the world.However, Watermelon mosaic virus (WMV) is a limited factor to the watermelon planting for its huge damage.As other potyvirus number, WMV is also has a positive single strand RNA genome, which is bound by a viral protein genome-linked (Vpg) at the 5 terminal of genome.