应用SSCP技术分析我国柑橘衰退病毒的混合感染

Analysis of mixed infection of Citrus tristeza virus in China by SSCP

以随机采样的方式,从湖北、湖南和江西3省10县的柑橘产区收集242份温州蜜柑(CitrusunshiuMarc.)、橘(C.reticulataBlanco)、甜橙(C.sinensisOsbeck)和柚(C.grandisOsbeck)样品。对PAS-ELISA法初步检测呈阳性的样品进行柑橘衰退病毒(Citrustristezavirus,CTV)CP基因(coatingproteingene,CPgene)的RT-PCR扩增,结果来自14个样品采集地的120份样品感染了CTV,单个采样点的感染率为20.0%～71.4%,而总感染率达49.6%,表明CTV在这些地区广泛发生。单链构象多态性(single-strandconformationpolymorphism,SSCP)分析显示,120份CTV的CP基因RT-PCR的扩增产物共产生120种SSCP带型,而且存在广泛的混合感染。

242 samples of satsuma mandarin （Citrus unshiu Marc.）, tangerine （C. reticulata Blanco.）, sweet orange （C. sinensis Osbeck.） and pummelo （C. grandis Osbeck.） were randomly collected from ten counties of Hubei, Hunan, and Jiangxi. CP gene （coating protein gene） of Citrus tristeza virus （CTV） from samples preliminarily screened by PAS-ELISA was amplified by RT-PCR. The results of amphfication showed that 120 samples from fourteen sampling sites were all affected with CTV, the affecting rate of single site ranged from 20.0% to 71.4% and the total rate was up to 49.6%, and thus suggested that CTV extensively occurred in these regions. Single-strand conformation polymorphism （SSCP） analysis indicated that 120 amplified products of CP gene of CTV made up a profile of 120 kinds of SSCP haplotypes, and this showed that great mixed infection existed among CTV in these regions.