警惕侵入日本的病毒病,包括菌原体和立克次氏体的病害共56种。其中有50种是果树、马铃薯,甘薯、甘蔗和球根类等营养繁殖的植物病害。这些植物输入后,要进行一至二年的隔离栽培,实行最严格的检查。现选其中最重要的13种病毒病,就其分布、危害和病症等加以解说。 (一)果树的病毒病 1.柑桔僵化病毒和绿化病毒病(Citrus We are alert to 56 viruses that invade Japan and include diseases of mycoplasma and rickettsia. Of these, 50 are vegetatively vegetated plant diseases such as fruit trees, potatoes, sweet potatoes, sugar cane and bulbs. After these plants are imported, they must be isolated for one to two years and subjected to the most rigorous inspection. The 13 most important viral diseases are selected for their distribution, hazards and illnesses. (A) fruit tree virus disease 1. Citrus rigid virus and green virus disease (Citrus