来源于猕猴桃的柑橘叶斑驳病毒的RT-PCR检测及外壳蛋白基因序列分析

RT-PCR detection and sequence analysis of coat protein gene of Citrus leaf blotch virus infecting kiwifruit trees

柑橘叶斑驳病毒（Citrus leaf blotch virus，CLBV）为柑橘病毒属（Citrivirus）代表种。本研究采用RT-PCR技术从我国栽培猕猴桃上首次检测到CLBV．总检出率为13．3％。测定了5个CLBV分离物的外壳蛋白基因（coat protein gene，cp）序列，全长均为1092核苷酸（nt），分离物间印基因核苷酸和编码氨基酸序列相似性分别为83．2％～99．7％和91．9％～98．9％，这些分离物与新西兰报道的CLBV猕猴桃分离物M3．A核苷酸序列相似性仅为83％左右，与来源于柑橘及近缘种的CLBV分离物印基因核苷酸序列相似性为84％-86％。在基于该病毒印基因核苷酸序列的系统进化树中，本研究所测定的CLBV猕猴桃分离物与新西兰报道的除M3-A外的猕猴桃分离物聚在同一组群。研究结果为进一步明确CLBV在我国猕猴桃上的侵染和危害特点及建立该病毒的分子检测技术提供了重要信息。

Citrus leaf blotch virus （CLBV） is type species of the genus Citrivirus. In this study, CLBV was detected in kiwifruit （Actinidia spp.） plants grown in China for the first time by reverse transcription PCR （RT-PCR）. CLBV was tested in kiwifruit plants with a positive rate of 13.3%. The complete cp gene of five CLBV isolates was 1 092 nucleotides （nts） in length and shared 86.6%-99.7% nt and 96.4%-99.4% amino acid （aa） sequence identities with each other, respectively. However, they shared only about 83% nt identity with a kiwifruit isolate M3-A reported in New Zealand, and 84%-86% identity with CLBV isolates infecting citrus and its relatives. In the phylogenetic tree basing on nucleotide sequences of their cp genes, CLBV isolates identified in the present study clustered into a group with New Zealand kiwifruit CLBV isolates except for isolate M3-A. Our studies would be favorable to understand the occurrence of this disease in China and to establish a more efficient RT-PCR method for rapid detection of the CLBV infecting kiwifruit trees.