含卫星RNA的黄瓜花叶病毒弱株系的分离鉴定及在病毒病防治上的应用

从豌豆上分离获得黄瓜花叶病毒分离物ＣＭＶＰ１，摩擦接种９科２９种植物，ＣＭＶＰｌ在大多数植物上症状很轻或无任何症状，提纯的病毒颗粒为球形，直径约２８ｎｍ，病毒衣壳蛋白亚基分子量约２７．５ｋＤ，所含核酸有五个组份，即ＣＭＶＰ１含有卫星ＲＮＡ。ＣＭＶＰ１接种三生烟后８－１２天内呈轻花叶，此时组织中病毒含量最高，随后症状消失，去除卫星ＲＮＡ能加重ＣＭＶＰ１在番茄上的症状，因而是卫星ＲＮＡ减轻了ＣＭＶＰｌ的病状。当ＣＭＶＰ１保护接种番茄后攻强毒，番茄发病率低，病情轻，保护率达９０％以上，并有一定的刺激生长作用，还能提早开花４天，植株结果数增多，成熟果实的颜色、形态、品质和重量均正常。ＣＭＶＰ１对烟草亦具有很好的保护效果。保护接种的植株能明显减少强毒株侵染，可减少９０％以上。

Isolation of a Nild Strain of CMV with Satellite RNA and Cross Protection against Virulent Strains

CMV isolate(CMVP 1)containing satellite RNA was obtained from pea(Pisum sativum)in Jiangsu province in 1990.Twenty-nine plant species representing nine families were inoculated mechanically with CMVP l and no symptoms or only mild symptoms were found.In Nicotina tabacum-Samsum,CMVP 1 caused Slight mosaic 8-16 days after inoculation and the infectivity redched the highestlevel at this time then the symptoms disappeared and the infectivity decreased.When satellite RNAwas eliminated by electrophoresis,CMVPl caused severe symptoms in tomato,so mild spoptoms of CMVPl in plant species were controlled by satellite RNA.In greenhouse crase protection tests,tomatoplants were first vaccinated with CMVP1 and cllallenge-inoculated with a virulent strain 5 to 30 dayslater,the disease incidence of vaccinated plant decreesed by 77.80%and the protective rate of the vaccination was higher than 90%,The average height and width of vaccinated plants were greater thanthose of healthy plants,so vaccination with CMVP1 had some favourable effects on tomato growth.Vaceinated plants flowered four days earlier and the fruit shape,color and weight were as normal as that of healthy plants,No synergistic effects were observed in mixed infection of CMVPl and TMV,which is another common virus in tomato,High protective effects were also observed in tobaccos.Preinoculation of CMVP1 could decrease infectivity of virulent strain by more than 90%.