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病毒病是影响云南省蚕豆生产的重要病害。对采集的蚕豆病毒病标样进行了组织印迹法检测,表明菜豆黄花叶病毒(BYMV)是最主要的病原。据此,以BYMV基因的保守序列设计了一对特异性引物,用BYMV的5个中国云南蚕豆分离物和1个叙利亚蚕豆分离物侵染的蚕豆叶片总RNA为模板,RT-PCR扩增获得了长度为907bp的目标片段。序列分析显示,此片段中包含822bp的外壳蛋白序列。6个分离物间的外壳蛋白核苷酸和推导编码蛋白质的氨基酸序列的同源性分别为86.4%～100.0%和96.7%～100.0%。与GenBank登录的34个具有完整外壳蛋白序列的BYMV分离物进行同源性和系统进化树分析的结果表明,6个分离物在核苷酸和氨基酸水平上与其它分离物的同源性分别为79.1%～97.9%和83.5%～98.5%,BYMV中国蚕豆分离物与日本蚕豆分离物同源性最高。外壳蛋白基因的序列特征揭示,在BYMV中的蚜传相关基序为NAG。
Virus disease is an important disease that affects the production of faba bean in Yunnan Province. The collected virus samples of Vicia faba were detected by histological blot, which indicated that BYMV was the most important pathogen. Based on this, a pair of specific primers was designed based on the conserved sequence of BYMV gene. The total RNA of Vicia faba leaves infected by 5 Chinese Yunnan faba bean isolates from BYMV and 1 Syrian faba isolate was used as a template for RT-PCR amplification The length of 907bp target fragment. Sequence analysis showed that this fragment contains 822bp of the coat protein sequence. The homologies of coat protein nucleotide and deduced amino acid sequence of the six isolates were 86.4% -100.0% and 96.7% -100.0%, respectively. The results of homology and phylogenetic tree analysis of 34 BYMV isolates with complete coat protein sequences registered in GenBank showed that the homologies of the 6 isolates with other isolates at the nucleotide and amino acid levels were 79.1% -97.9% and 83.5% -98.5%, respectively. BYMV isolates from China showed the highest homology with Japanese faba bean isolates. The sequence characteristics of coat protein genes revealed that the aphid-associated motif in BYMV is NAG.