病毒病害近年逐渐引起人们更大的注意,因为由病毒病害所造成的损失日益严重。有时病毒病害可以威胁某种植物的存在,甚至导致毁灭。如南非洲可可树的肿枝病就是突出的一个病例,近年来因病致死者每年在千万株以上,南非洲可可树差不多都要被消灭了。病毒是一种活的蛋白质,也可以说是一种最简单的生物,它是渗透性的,能渗透侵入所有植物体内的 Virus diseases have drawn increasing attention in recent years because of the growing losses caused by viral diseases. Sometimes viral diseases can threaten the existence of a plant and can even lead to destruction. For example, the swollen branch disease of the cocoa tree in South Africa is one of the prominent cases. In recent years, more than 10 million people died from the disease each year, and the cacao tree in South Africa is almost eliminated. The virus is a living protein, it can be said that the most simple organism, it is permeable, can penetrate into all plants