病毒病是白菜三大痛害(另有霜霉病、软腐病)中发病最早的一种。幼苗发病后,心叶出现明脉及沿脉退绿,产生浓绿与淡绿相间的花叶,叶片皱缩,生长缓慢、停滞,重者枯死。成株感病多为苗期受病而残留下来的。这 Virus disease is the three major diseases of cabbage (downy mildew, soft rot disease) in the earliest one. Emergence of seedlings, the heart of the Ming veins and green along the veins, resulting in thick green and light green leaf mosaic, leaf shrinkage, slow growth, stagnation, severe cases dead. Adult plant disease and seedling disease and residual. This