Liu L Z, Chen Y Y, Zhu W M
Horticultural Research Institute, Shanghai Academy of Agricultural Sciences (SAAS), Shanghai Key Lab of Protected Horticultural Technology, Shanghai, 201106, China.
Plant Dis. 2010 Apr;94(4):485. doi: 10.1094/PDIS-94-4-0485A.
Melon (Cucumis melo L.) plants in commercial fields in Shanghai, Jiangsu, and Zhejiang exhibited stunting, deformation, interveinal chlorosis, and leaf mottling in the spring of 2008. In addition, adult and immature whiteflies (Bemisia tabaci biotype B) were present in these melon fields. Thirty-two symptomatic leaf samples were collected from these fields for further analysis (9 from Nanhui County in Shanghai, 11 from Fengxian County in Shanghai, 6 from Kunshan County of Jiangsu, and 6 from Jiashan County of Zhejiang). Total RNA was extracted from these samples along with asymptomatic control plants and screened for the presence of Cucurbit yellow stunting disorder virus (CYSDV) by using primers specific to genes encoding coat protein (2) and HSP70h (1) of CYSDV through reverse transcription (RT)-PCR methods. RNA was successfully extracted from 31 of 32 symptomatic samples. All 31 symptomatic leaf samples tested with coat protein primers were positive for CYSDV and yielded the expected fragment length of 394 bp. The RT-PCR products of the coat protein gene from all 31 isolates were cloned and found to be identical in sequence. Thus, only one was deposited in GenBank (No. GU189240). The submitted sequence of the amplified part of the coat protein gene was 99% identical to the sequence of coat protein gene of CYSDV from Jordan, France, and Florida (GenBank Accession Nos. DQ903107, AY204220, and EU596528, respectively) and 98% identical to that of an isolate from Spain (GenBank Accession No. AJ243000). Similarly, all 31 samples were also positive for CYSDV with the primers specific to HSP70h and yielded the expected fragment length of 175 bp. The RT-PCR products of the HSP70h gene from these isolates were also cloned and found to be identical in sequence. The sequence of the amplified portion of the HSP70h gene was found to be identical to the sequence of HSP70h of CYSDV deposited in GenBank (No. AJ439690.2). CYSDV was noticed in all three surveyed regions and the percentage of disease incidence was approximately 68% in all these regions. The occurrence of CYSDV has been previously reported in Europe (Spain and France), southern Asia (Iran and Jordan), North America (United States and Mexico), and other countries (1). To our knowledge, this is first report of CYSDV in China. References: (1) Y.-W. Kuo et al. Plant Dis. 91:330, 2007. (2) J. E. Polston et al. Plant Dis. 92:1251, 2008.
2008年春季，上海、江苏和浙江等地商业种植田中的甜瓜（Cucumis melo L.）植株出现生长迟缓、变形、叶脉间黄化和叶片斑驳症状。此外，这些甜瓜田中还存在成虫和未成熟的烟粉虱（Bemisia tabaci biotype B）。从这些田中采集了32份有症状的叶片样本用于进一步分析（上海南汇县9份、上海奉贤县11份、江苏昆山县6份、浙江嘉善县6份）。从这些样本以及无症状对照植株中提取总RNA，并通过逆转录（RT）-PCR方法，使用针对葫芦科黄化矮缩病毒（CYSDV）衣壳蛋白基因（2）和HSP70h基因（1）的特异性引物，检测CYSDV的存在。32份有症状的样本中有31份成功提取到RNA。用衣壳蛋白引物检测的所有31份有症状叶片样本对CYSDV均呈阳性，并产生了预期的394 bp片段长度。来自所有31个分离株的衣壳蛋白基因的RT-PCR产物被克隆，发现序列相同。因此，仅将其中一个存入GenBank（编号GU189240）。扩增的衣壳蛋白基因部分的提交序列与来自约旦、法国和佛罗里达的CYSDV衣壳蛋白基因序列分别有99%的同一性（GenBank登录号分别为DQ903107、AY204220和EU596528），与来自西班牙的一个分离株的序列有98%的同一性（GenBank登录号AJ243000）。同样，所有31份样本用针对HSP70h的特异性引物检测对CYSDV也呈阳性，并产生了预期的175 bp片段长度。这些分离株的HSP70h基因的RT-PCR产物也被克隆，发现序列相同。发现扩增的HSP70h基因部分的序列与存入GenBank的CYSDV的HSP70h序列（编号AJ439690.2）相同。在所有三个调查地区均发现了CYSDV，所有这些地区的发病率约为68%。此前在欧洲（西班牙和法国）、南亚（伊朗和约旦）、北美（美国和墨西哥）及其他国家已报道过CYSDV的发生（1）。据我们所知，这是CYSDV在中国的首次报道。参考文献：（1）Y.-W. Kuo等人，《植物病害》91:330，2007年。（2）J. E. Polston等人，《植物病害》92:1251，2008年。
