It was identified that the virus source of cruciferous vegetable diseases in China was mainly turnip mosaic virus (TuMV), followed by cucumber mosaic virus (CMV), tobacco mosaic virus (TMV) and radish mosaic virus (RMV). Among them, the first three viruses are the main ones, but they are slightly different from place to place.

TuMV belongs to potato y virus. The granules are linear, with a size of 700 ~ 760 nm3 ~15 μ m. The ultrathin section of the diseased tissue can be seen as a wheel-shaped inclusion under the electron microscope. The passivation temperature is 55 ~ 65℃, the dilution limit is 2000 ~ 5000 times, and the in vitro preservation period is1~ 7d. TuMV not only infects cruciferous vegetables such as Chinese cabbage, rape, cabbage, cauliflower, radish, mustard and turnip, but also infects spinach, chrysanthemum and plantain.