中国野生柑橘上衰退病毒分离株分子特征分析

 【目的】了解中国野生柑橘上携带柑橘衰退病毒（CTV）分离株的CP/HinfⅠRFLP组群构成和分子特征。【方法】运用RT-PCR对采自中国云南、广西、四川、湖南、江西等省11个野生柑橘上CTV分离株的病毒衣壳蛋白基因(CPG)进行扩增，利用RFLP和SSCP对CPG进行分析，并将测定的CPG序列进行同源性比较和聚类分析。【结果】发现野生柑橘上11个CTV分离株以单一组群感染为主；这些CTV分离株CPG的核苷酸序列和相应的氨基酸序列同源性分别为92.5％～99.5％和95.0％～100％；与GenBank收录的9个全基因组CTV分离株的相应基因序列进行聚类分析，其核苷酸序列和氨基酸序列同源性分别为92.1％～98.8％和94.6％～100％。【结论】序列同源性比较说明CTV CPG具有高度保守性，同时系统进化分析表明收集到的野生CTV分离株与国外分离株分属5大类群，具有较复杂的亲缘关系。

Molecular Characterization of Citrus Tristeza Virus Isolates in Chinese Wild Type Citrus

【Objective】This study was conducted to investigate the CP/Hinf I RFLP groups and molecular characterization of citrus tristeza virus (CTV) infection Chinese wild citrus.【Method】The cDNA of coat protection gene (CPGs) were amplified and sequenced from 11 isolates of CTV collected from wild citrus of Yunnan, Guangxi, Sichuan, Hunan and Jiangxi provinces, using RT-PCR and sequencer. The products of CPGs were analyzed by RFLP and SSCP, their CPGs sequences were subjected to sequence analysis and compared with CPGs sequences of 9 referred CTV isolates from GenBank by BioEidt and MEGA software.【Result】Comparison results showed that CPGs nucleotide sequences and amino acid sequences of the 11 CTV isolates shared homology of 92.5%-99.5% and 95.0%-100% , respectively，and of 92.1%-98.8% and 94.6%-100% with those of 9 referred CTV isolates. RFLP and SSCP analysis on CPGs of 11 CTV isolates, the results demonstrated that single CP/Hinf I RFLP groups infected the mostly wild citrus.【Conclusion】Phylogenetic analysis of the 11 CTV isolates and 9 foreign referred CTV isolates showed that CPGs were highly conserved. It is suggested there exists complicated genetic relationship among the 11 CTV isolates and the 9 referred CTV isolates.