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从新疆鄯善县、甘肃瓜州县和河南通许县采集表现瓜类蚜传黄化病毒(Cucurbit aphid-borne yellows virus,CABYV)症状的甜瓜叶片样品63份,利用反转录PCR(RT-PCR)检测,从阳性样品中选取25个分离物扩增出1.4 kb的片段,并对其序列进行分析。结果表明:63份样品中,36份为CABYV阳性;获得的序列包括部分3′端的依赖RNA的RNA聚合酶(RdRp)基因、非编码区(NCR)和全长外壳蛋白(CP)基因。随机选取25个分离物的CP基因与GenBank中的序列进行比对,其序列相似性为93.2%~100%。通许分离物间序列相似性为98.8%~99.8%,瓜州分离物间序列相似性为98.2%~100%,鄯善分离物间序列相似性为99.2%~100%,组内表现出极高的同源性。基于其部分RdRp基因、NCR及CP基因序列构建的系统进化树表明:25个CABYV分离物与中国及周边地区(泰国、韩国等)的分离物聚为一簇,而与欧洲地区分离物距离较远,说明了该病毒分子变异与分离物的地理分布有关。
Sixty-three melon leaves samples expressing Cucurbit aphid-borne yellows virus (CABYV) were collected from Shanshan County of Xinjiang Province, Guazhou County of Gansu Province and Tongxu County of Henan Province. Reverse transcription PCR (RT-PCR) ). A total of 25 isolates were selected from the positive samples to amplify a 1.4 kb fragment, and their sequences were analyzed. The results showed that out of 63 samples, 36 were positive for CABYV. The obtained sequences included part of 3 ’RNAR-dependent RNA polymerase (RdRp), non-coding region (NCR) and full length coat protein (CP) genes. The CP genes of 25 isolates were randomly selected and compared with the sequences in GenBank. The sequence similarity was 93.2% ~ 100%. The similarities among the isolates of Tongluo were 98.8% -99.8%, the similarities among the isolates of Guazhou were 98.2% -100%, and the similarities between the two isolates were 99.2% -100% Homology. Phylogenetic tree based on partial RdRp gene, NCR and CP gene sequences showed that 25 CABYV isolates clustered with isolates from China and the surrounding areas (Thailand, South Korea, etc.) Far, indicating that the molecular variation of the virus is related to the geographical distribution of isolates.