柑橘速衰病毒CP基因的序列变异性分析  

Analysis of Sequence Variability in CP Gene of Citrus tristeza virus

作　　者：张建坤[1] 洪霓[1] 王国平[1] 

机构地区：[1]华中农业大学植物科学技术学院湖北省作物病害监测与安全控制重点实验室,武汉430070

出　　处：《农业生物技术学报》2006年第2期259-264,共6页Journal of Agricultural Biotechnology

基　　金：国家高技术研究与发展计划(863)项目(2001AA241142)资助

摘　　要：以提取的宽皮橘(CitrusreticulataBlanco)总RNA为模板,用RT-PCR扩增柑橘速衰病毒(Citrustristezavirus,CTV)的外壳蛋白基因(CP),扩增产物经克隆与测序证实,来自湖南道县和江西崇义的3份样品(HN、JX-1和JX-2)都感染了CTV。单链构象多态性(single-strandconformationpolymorphism,SSCP)分析表明,来源于3份样品的CTV的CP基因在遗传上存在变异,其中来自HN和JX-1的CTV的CP基因序列仅含有1种序列类型,而来自JX-2的CP基因序列群体则含有2种主序列。序列分析表明,克隆HN-K与葡萄牙分离物28C和以色列茎陷分离物VT的同源性均为98%;克隆JX-1-1与印度茎馅分!"Pune和Bangalore的同源性分别达98%和99%;克隆JX-2-7、JX-2-17与日本苗黄分离物NUagA和美国加利福尼亚严重茎陷分离物SY568相比,同源性为97%%￣98%;4个克隆与佛罗里达速衰分离物T36、弱毒分离物T30和西班牙弱毒分离物T385的同源性仅有91%%￣93%。系统发育分析显示,4个中国克隆分属3个不同的族,与地理起源不同的茎陷或苗黄分离物的亲源关系更近,而与速衰和弱毒分离物的亲源关系更远,暗示CTV的地理起源与其核苷酸距离之间没有相关性。Using total RNA as template extracted from three citrus （Citrus reticulata Blanco） samples （HN, JX-1 and JX-2） colleered from Daoxian, Hunan and Chongyi, Jiangxi, CP gene of Citrus aisteza virus （CTV） was amplified by RT-PCR. The results of cloning and sequencing of amplified products demonstrated that three samples were affected with CTV. The results for single-strand conformation polymorphism （SSCP） analysis showed that genetic variation existed among the CPgenes of CTV from three samples. The CP genes of CTV from HN and JX-1 contained a unique sequence type, but that from JX-2 had a population of sequence types, two of which were predominant. Sequence analysis results showed that clone HN-K had 98% nucleotide sequence identity with Portuguese isolate 28C and Israeli stem pitting isolate VT; clone JX-1-1 98%-99% with Indian isolates Pune and Bangalore; clone JX-2-7 and JX-2-17 97%-98% with Japanese seedling yellows isolate NUagA and Californian severe stem pitting isolate SY568. All four clones shared only 91%-93% identity with Floridian quick decline isolate T36, mild isolate T30 and Spain mild isolate T385. Phylogenetic tree analysis revealed that four Chinese clones appeared in three different clusters, shared high homology with seedling yellows or stem pitting isolates from different geographical origins but low homology with quick decline and mild isolates, and these suggested that there had no correlation between geographic origin of CTV and their nucleotide distances.

关 键 词：柑橘速衰病毒(CTV) CP基因 RT-PCR 单链构象多态性(SSCP) 系统发育分析 

分 类 号：S188[农业科学—农业基础科学]