京郊大蒜病毒病的研究及其鳞茎中病毒的脱除

ON THE GARLIC VIROSIS IN THE VICINITY OF BEIJING,WITH SPECIAL REFERENCE TO THE ELIMINATION OF VIRUSES FROM THE BULB

京郊大蒜病毒病发生普遍,主要症状为条纹花叶、矮化和叶片扭曲畸形。病体细胞中含大量线状病毒粒体和风轮状内含物。线状病毒粒体长度范围为250—1875nm,以长度550—800nm粒体居多。其中长700—800nm的粒体被鉴定为大蒜花叶病毒(GMV),回接脱毒大蒜叶片产生条纹花叶症状。血清学鉴定表明GMV与洋葱黄矮病毒(OYDV)有近缘关系。长度500—600nm的粒体可能为大蒜潜隐病毒(GLV),回接脱毒大蒜不产生花叶症状。下述两种病毒为京郊大蒜的主要病毒。此外,个别标样含烟草花叶病毒,但不是大蒜的主要病毒。对800nm以下线状病毒粒体归属尚待研究。应用营养茎尖、生殖茎尖和根尖分生组织培养技术,可以脱去上述主要病毒,获得脱毒大蒜。

Jn the vicinity of Beijing garlic plants were infected by viruses prnducingstreak mosaic as well as dwarfing and curling of the leaves,and resulting inthe reduction of size of bulb.This disease was demonstrated to be caused byseveraj viruses which could be transmitted either by the sap of the diseasedplants or by peach aphids.Allium fistulosum,A.cepa.A.porrum and Vicia fabawere infected systemically by sap inoculation.Local lesions were producedon the inoculated leaves of Gomphrena globosa,Chenopodium amaranticola,C.quinoa and Tetragonia teiragonioides.In addition,the sap from afew disaeased garlic plants could infect Nicotiana glutinosa locally,andPhysalis floridana systemically.Electron microscopic observations of the dipsof all the above host species,except N.glutinosa and P.floridana with negativestaining revealed that there are flexuous filamentous particles 250-1875 nm long,with 600-800 nm as the norm.The particles which were 700-800nm long wereidentified to be Garlic Mosaic Virus (GMV).This virus caused streak mosaicsymptoms on leaves of virus-free garlic plants.Immuno electron microscopyidentifications with OYDV antiserum showed that GMV is related to OYDV.Another virus with particles about 650 nm long belongs to Garlic Latent virus(GLV) which do not cause any mosaic symptoms on virus-free garlis plants.However the dips of the last two species contained rod-shaped particles,300nm in length,belonging to TMV.It is not the main pathogen for garlic virusdisease.Other particles measured longer than 800 nm remained to be identi-fied. With reproductive and vegetative shoot apical meristem culture,virus-freegarlic clones have been obtained.