Dianthus amurensis, commonly known as Amur Pink, is a species of the genus Dianthus in the family Caryophyllaceae. This perennial Dianthus is also a Chinese medicinal herb. In August 2012, mosaic, leaf cupping, leaf distortion, reduction in leaf size, and flower-breaking symptoms were observed on some D. amurensis plants in a Chinese herb nursery in Changchun, Jilin Province, China. Disease incidences ranged from 40 to 50% in different plots. Symptoms on diseased D. amurensis were similar to those on the diseased D. caryophyllus, D. barbatus, and D. japonicus. The symptoms resembled to those caused by Carnation vein mottle virus (CVMoV), a member of genus Potyvirus in the family Potyviridae (3). CVMoV infects carnations (D. caryophyllus) worldwide and causes a serious disease. To investigate the presence of CVMoV, leaf samples were collected from three symptomatic plants and tested by dot-ELISA using universal potyvirus group monoclonal antibody (Agdia, Inc., Elkhart, IN). The antibody reacted with the diseased samples, supporting the presence of a potyvirus. To identify the potyvirus species, total nucleic acids were extracted from the diseased samples by a CTAB method (2) and used as template in RT-PCR with potyvirus universal primers Sprimer and M4T (1). An amplicon of the expected size (~1.7 kb) was obtained from all three diseased samples. The amplicons were cloned into pMD18-T vector (TaKaRa, Dalian, China) and sequenced. Sequences obtained from all three samples were identical and deposited in GenBank (Accession No. KJ605654). BLAST search showed that the nucleotide sequence shared 97 and 98% identity with a Japanese CVMoV isolate infecting D. japonicus (AB017630) (3) and a Korean CVMoV isolate (AY512554), respectively. The results confirmed the association of CVMoV with the disease on D. amurensis. To determine the pathogenicity of CVMoV to D. amurensis plants, purified CVMoV from the diseased plants were used to inoculate to healthy Dianthus spp. plants. Inoculated Dianthus spp. plants also showed the symptoms of mottle, leaf cupping, and leaf distortion, and CVMoV could be detected by RT-PCR from these plants. The result confirms that CVMoV is the causal agent of the disease. To our knowledge, this is the first report of CVMoV infection in D. amurensis. Since D. amurensis is economically important in China, proper virus management strategies for the cultivation of this crop should be adopted.
References: (1) J. Chen et al. Arch. Virol. 146:757, 2001. (2) R. Li et al. J. Virol. Methods 154:48, 2008. (3) T. Sasaya et al. J. Gen. Plant Pathol. 66:251, 2000.