罹病康乃馨之Carnation mottle virus的分離與鑑定

Virus cultures were isolated from leaves of carnation (Dianthus caryophyllus L.) and mini-carnation [Dianthus caryophyllus hybrid Kooij (Echo kgr)] showing viral disease-like symptoms of yellow necrotic spots and yellow mottle beginning on upper leaves in the fields in central Taiwan. Isometric particles about 32-33 nm in diameter were found in crude saps of diseased tissues. Similar particles were also observed in the cytoplasm of the mesophyll cell in ultrathin sections prepared from infected D. caryophyllus and D. chinensis. SDS-polyacrylamide gel electrophoresis showed that the virus contains one structural polypeptide about 40 kDa. Serological tests with double immunodiffusion test and double antibody sandwich-enzyme-linked immunosorbent assay showed that the virus reacted positively with an antiserum prepared against Carnation mottle virus (CarMV). The coat protein (CP) gene of the virus was amplified by reverse transcription-polymerase chain reaction (RT-PCR), cloned, and sequenced using primers designed from a conserved sequence of CarMV. Comparisons of the 1047 -nucleotide CP gene with those of 23 CarMV isolates available in GenBank showed that the virus shared 95.6-97.9% nucleotide identity and 98.0-99.1% amino acid identity. Our results demonstrate that the virus infecting carnation is an isolate of CarMV. This is the first report of CarMV infecting carnation in Taiwan.