小西葫芦黄花叶病毒山东南瓜和丝瓜分离物全基因组序列分析

在山东泰安采集到两个表现黄花叶症状的丝瓜和南瓜样品中检测到小西葫芦黄花叶病毒(Zucchini yellow mosaic virus,ZYMV);通过RT-PCR和RACE方法获得了两个分离物的全基因组序列,分别命名为CN:Cm:17(丝瓜分离物)和CN:Lc:17(南瓜分离物)。结果表明,CN:Cm:17和CN:Lc:17基因组除Poly(A)尾巴外,分别含有9 593和9 591个核苷酸(Nucleotides,nt),通过多聚蛋白策略编码一个含3080个氨基酸的多聚蛋白。CN:Cm:17和CN:Lc:17在氨基酸水平上一致率为96.7%;CN:Cm:17与韩国分离物KR:RDA:07的氨基酸一致率最高(97.8%); CN:Lc:17与CN:CJLX30535:14和CN:spider131932:13的一致率最高(98.4%)。重组分析发现,CN:Lc:17具有显著重组事件,为KR:KR-PA:05和CN:Cm:17的重组体。基于多聚蛋白编码序列的系统进化聚类结果显示分组与分离物的地理起源存在密切相关性,所有中国分离物分别聚集在A-Ⅴ和A-Ⅵ亚组。

Complete Genomic Sequence Analysis of Zucchini yellow mosaic virus Pumpkin and Loofah Isolates from Shandong Province

Zucchini yellow mosaic virus（ZYMV）is a major virus infecting cucurbit crops. ZYMV was detected in leaf samples of loofah and pumpkin displaying symptoms of yellowing and mosaic collected from Tai’an，Shandong Province. Their complete genome sequences were determined using RT-PCR and 5′ RACE，the resulting complete genomes were named as CN:Cm:17 and CN:Lc:17，respectively. Sequencing results showed that the complete genome excluding poly(A) tail of CN:Cm:17 and CN:Lc:17 was 9 593 and 9 591 nucleotides（nt），respectively，encoding a polyprotein of 3 080 amino acids. Amino acid sequence identity between CN:Cm:17 and CN:Lc:17 was 96.7%. Isolate CN:Cm:17 shared the highest sequence identity with KR:RDA:07 at amino acid level，CN:Lc:17 showed the highest sequence identity with CN:CJLX30535:14 and CN:spider131932:13. Recombinant analysis revealed that CN:Lc:17 was recombinant of isolates of KR:KR-PA:05 and CN:Cm:17. Phylogenetic analysis based on polyprotein- encoding sequences suggested a high correlation between phylo-groups and their geographical origins. All Chinese isolates were grouped in A-Ⅴ and A-Ⅵ，respectively.