Rao W-L, Zhang Z-K, Li R
Kunming B&T Agricultural School, Kunming 650034, China.
Biotechnology and Genetic Resources Institute, Yunnan Academy of Agricultural Sciences, Kunming 650223, China.
Plant Dis. 2009 Apr;93(4):425. doi: 10.1094/PDIS-93-4-0425B.
Plants in the genus Prunus of the family Rosaceae are important fruit and ornamental trees in China. In June of 2007, sweet cherry (Prunus avium) trees with mottling and mosaic symptoms were observed in a private garden near Kunming, Yunnan Province. Twenty-four samples, six each from sweet cherry, sour cherry (P. cerasus), flowering cherry (P. serrulata), and peach (P. persica) were collected from trees in private and community gardens in the area. The peach and sour and flowering cherry trees did not show any symptoms. Total nucleic acids were extracted using a cetyltrimethylammoniumbromide (CTAB) extraction method, and the extracts were tested for the following eight viruses by reverse transcription (RT)-PCR: American plum line pattern virus, Apple chlorotic leaf spot virus, Cherry green ring mottle virus, Cherry necrotic rusty mottle virus, Cherry virus A (CVA), Little cherry virus 1, Prune dwarf virus, and Prunus necrotic ringspot virus. Only CVA was detected in two symptomatic sweet cherry trees by RT-PCR with forward (5'-GTGGCATTCAACTAGCACCTAT-3') and reverse (5'-TCAGCTGCCTCAGCTTGGC-3') primers specific to an 873-bp fragment of the CVA replicase gene (2). The CVA infection of the two trees was confirmed by RT-PCR using primers CVA-7097U and CVA-7383L that amplified a 287-bp fragment from the 3'-untranslated region (UTR) of the virus (1). Amplicons from both amplifications were cloned and sequenced. Analysis of the predicted amino acid sequences of the 873-bp fragments (GenBank Accession Nos. EU862278 and EU862279) showed that they were 98% identical with each other and 97 to 98% with the type isolate of CVA from Germany (GenBank Accession No. NC_003689). The 286-bp sequences of the 3'-UTR (GenBank Accession Nos. FJ608982 and FJ608983) were 93% identical with each other and 93 to 98% with the type isolate. The sequence indicated that the three isolates were very similar and should be considered to be the same strain. CVA is a member of the genus Capillovirus in the family Flexiviridae and has been previously reported in Europe, North America, and Japan. The contribution of CVA to the symptoms observed and its distribution in China remain to be evaluated. To our knowledge, this is the first report of CVA in sweet cherry in China. References: (1) M. Isogai et al. J. Gen. Plant Pathol. 70:288. (2) W. Jelkmann. J. Gen. Virol. 76:2015, 1995.
蔷薇科李属植物是中国重要的果树和观赏树木。2007年6月，在云南省昆明市附近的一个私人花园中，观察到有斑驳和花叶症状的甜樱桃（Prunus avium）树。从该地区私人和社区花园的树木上采集了24个样本，分别从甜樱桃、酸樱桃（P. cerasus）、樱花（P. serrulata）和桃（P. persica）树上各采集6个样本。桃树以及酸樱桃树和樱花树未表现出任何症状。使用十六烷基三甲基溴化铵（CTAB）提取法提取总核酸，并通过逆转录（RT）-PCR对提取物检测以下8种病毒：美国李线条病毒、苹果褪绿叶斑病毒、樱桃绿环斑驳病毒、樱桃坏死锈斑驳病毒、樱桃病毒A（CVA）、小樱桃病毒1、李矮缩病毒和李坏死环斑病毒。使用针对CVA复制酶基因873 bp片段的正向引物（5'-GTGGCATTCAACTAGCACCTAT-3'）和反向引物（5'-TCAGCTGCCTCAGCTTGGC-3'）进行RT-PCR，仅在两棵有症状的甜樱桃树中检测到CVA（2）。使用引物CVA-7097U和CVA-7383L通过RT-PCR确认了这两棵树的CVA感染情况，该引物从病毒的3'-非翻译区（UTR）扩增出一个287 bp的片段（1）。两次扩增的扩增产物均进行克隆和测序。对873 bp片段预测氨基酸序列的分析（GenBank登录号：EU862278和EU862279）表明，它们彼此之间的同源性为98%，与来自德国的CVA模式分离株的同源性为97%至98%（GenBank登录号：NC_003689）。3'-UTR的286 bp序列（GenBank登录号：FJ608982和FJ608983）彼此之间的同源性为93%，与模式分离株的同源性为93%至98%。该序列表明这三个分离株非常相似，应被视为同一菌株。CVA是柔线病毒科毛病毒属的成员，此前在欧洲、北美和日本有过报道。CVA对所观察到症状的影响及其在中国的分布情况仍有待评估。据我们所知，这是中国甜樱桃中首次报道CVA。参考文献：（1）M. Isogai等人，《植物病理学报》70:288。（2）W. Jelkmann，《病毒学杂志》76:2015，1995。
