title: Characterization of Citrus tristeza virus strains from southern China based on analysis of restriction patterns and sequences of their coat protein genes.
abstract: Citrus tristeza virus (CTV) isolates collected from southern China were characterized by biological indexing on citrus indicators, restriction fragment length polymorphism (RFLP), and bi-directional reverse transcription-polymerase chain reaction (BD-PCR) analysis of their coat protein (CP) genes. Of the 30 isolates, only two isolates, N3 and N4, did not induce visible symptoms. Twenty-eight other isolates induced stem pitting and vein clearing, plant stunting, and leaf yellowing symptoms on Mexican lime, Duncan grapefruit, and sour orange seedlings. In BD-PCR analysis, a 392-bp fragment specific for the mild strains was amplified from isolates N3 and N4, and a 320-bp fragment specific for the severe strains was produced from the other 28 isolates. The RFLP analysis for RT-PCR products of the CP gene with restriction enzyme HinfI identified seven groups representing groups I-VI and a new group, which was not involved in the seven groups defined by Gillings (J Virol Methods 44:305-317, 1993). The sequences of the CP genes from 12 Chinese CTV isolates showed a high divergence, with 91.5-99.7% identities at the nucleotide level and 94.2-99.6% identities at the amino acid level. Our results suggest that the composition of CTV populations from China has a high genetic diversity in the CP gene.
authors.affiliation: College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China.
authors.forename: Bo
authors.initials: B
authors.lastname: Jiang
authors.forename: Ni
authors.initials: N
authors.lastname: Hong
authors.forename: Guo-Ping
authors.initials: GP
authors.lastname: Wang
authors.forename: John
authors.initials: J
authors.lastname: Hu
authors.forename: Jian-Kun
authors.initials: JK
authors.lastname: Zhang
authors.forename: Cai-Xia
authors.initials: CX
authors.lastname: Wang
authors.forename: Yong
authors.initials: Y
authors.lastname: Liu
authors.forename: Xu-Dong
authors.initials: XD
authors.lastname: Fan
mesh_terms: D000595:Amino Acid Sequence; D036022:Capsid Proteins / Q000235:genetics*; D002681:China; D002957:Citrus / Q000821:virology*; D017790:Closterovirus / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D008969:Molecular Sequence Data; D010802:Phylogeny; D010935:Plant Diseases / Q000821:virology*; D012150:Polymorphism, Restriction Fragment Length; D016415:Sequence Alignment
chemical_list: D036022:Capsid Proteins