Submitted to: Plant Disease
Publication Type: Research Notes
Publication Acceptance Date: 1/9/2009
Publication Date: 4/1/2009
Citation: Rao, W.L., Zhang, Z.K., Li, R. 2009. First Report of Cherry virus A in Sweet Cherry Trees in China. Plant Disease. 93:425. Interpretive Summary: Stone fruits such as almond, apricot, cherry, peach, and plums are important fruit and ornamental plants worldwide. These perennial crops are usually propagated by grafting and, therefore, are easily infected with viruses when contaminated material is used as a propagation source. Cherry virus A (CVA) is a recently described virus infecting sweet cherry and has been found in Europe, North America, and Japan. We report here that CVA was detected in sweet cherry for the first time in China using a molecular assay. Analysis indicates that the CVA isolates found in China are very similar to that found in Germany. The wide distribution of this virus might be the result of the global movement of stone fruit germplasm as material is exchanged in efforts to improve horticultural and disease resistant characteristics. Although the association of CVA with any known cherry viral diseases is not clear, the virus might cause disease in mixed infections with other viruses. Therefore, it is desirable to add protocols to detect this virus in quarantine and certification programs. This information will be used by quarantine officials and by other scientists.
Technical Abstract: Plants in the genus Prunus of the family Rosaceae are important ornamental and fruit trees in China (1). In June 2007, sweet cherry (Prunus avium) trees with mottling and mosaic symptoms were observed in a private garden near Kunming, Yunnan Province. Twenty-four samples were then collected from sweet cherry, sour cherry (P. cerasus), flowering cherry (P. serrulata), and peach (P. persica) trees in private and community gardens in the area. Only the sweet cherry trees displayed symptoms. Total nucleic acids were extracted with a CTAB extraction method and used to test for eight viruses that are known to infect Prunus spp. by RT-PCR. Viruses that were assayed included 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 a RT-PCR assay with novel forward (5'-GTGGCATTCAACTAGCACCTAT-3') and reverse (5'-TCAGCTGCCTCAGCTTGGC-3') primers specific to an 873-bp fragment of the CVA replicase gene (2). The two amplicons were directly sequenced and the resulting sequences comprised 778 nucleotides encoding 247 amino acid residues (GenBank Accession No. EU862278 and EU862279). A BLAST search in GenBank showed 98% nucleotide identity and 99% amino acid identity with the type isolate of CVA from Germany (GenBank Accession no. NC_003689). CVA is a member of the genus Capillovirus in the family Flexiviridae and has been previously reported in Europe, North America, and Japan (3). The contribution, if any, of CVA to the symptoms observed and the distribution of the virus in China remain to be evaluated. To our knowledge, this is the first report of the presence of CVA in China. References: (1) J.-X. Wang. Deciduous Fruits. 5: 12-15, 2001. (2) W. Jelkmann. J. Gen. Virol. 76: 2015, 1995. (3) CABI. Distribution Map of Pl. Dis. Map 1009 (1), 2007.