Abstract: 【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.

Key words: Citrus tristeza virus, polymorphism analysis, Sequence comparison, Phylogenetics analysis