|Hsu, Hei Ti|
Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/15/2003
Publication Date: 12/15/2003
Citation: Jan, J.F., Chen, C.C., Hsu, H.T. 2003. Identification of Tomato Mosaic Virus Infecting Lisianthus in Taiwan. Plant Dis. 87:1537. Interpretive Summary: Lisianthus is an economically important ornamental crop around the world. It has become popular as potted plants and cut flowers in Taiwan. In the past few years, a virus disease was noticed in greenhouse- and field-grown lisianthus. The symptoms started with mosaic followed by necrosis on leaves of naturally infected lisianthus. Based on biological properties, electron microscopy and molecular analysis, a tomato mosaic virus (ToMV) was identified. Chlorotic and necrotic spots developed on lisianthus leaves one to two weeks after inoculation with the ToMV. The symptoms eventually became systemic in lisianthus. The virus is economically important to both lisianthus and tomato crops. This research is related to National Program Plant Health 303.
Technical Abstract: Diseased plants with mosaic symptoms followed by necrosis of leaf tissues were observed in lisianthus. Newly emergent leaves were curled and smaller compared with those on healthy plants. These symptoms greatly decreased the commercial value of the crop. Rigid rods, similar to tobamoviruses measuring 300 x 18 nm, were found consistently associated with symptomatic plants. A virus culture was isolated from diseased lisianthus and established and maintained in systemic hosts Nicotiana tabacum L. and N. benthamiana Domin. Chlorotic and necrotic spots developed on lisianthus leaves one to two weeks after inoculation with the virus; symptoms eventually became systemic. Virions, 300 x 18 nm, were purified from inoculated N. tabacum. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis showed that the virus contained one 18 kDa (Mr) polypeptide. A viral coat protein (CP) gene about 0.5 kb was amplified by reverse transcriptase-polymerase chain reaction from total RNA prepared from infected N. benthamiana using 5¿- gCgAgCCATggATTCTTACTCAATTACT as a forward and 5¿- ACTCTCggATCCTTAAgATgCAggTgCAgA as reverse primers. Comparison of the 480 nucleotide CP gene region with that of ToMV-OM (GenBank Accession No. X02144)(3) revealed 99.2% nucleotide identity and 99.4% amino acid identity. It shares, however, 74.4% nucleotide identity and 83.9% amino acid identity with CP genes of TMV-U1 (GenBank Accession No. AX040174) and TMV-vulgare (GenBank Accession No. J02415)(1). The virus induced local lesion responses similar to ToMV on inoculated N. tabacum cv White Burley, N. sylvestris Speg. & Comes, and Datura stramonium L. Inoculation of TMV, however, resulted in a systemic infection in theses plants. Results from sequence analysis and diagnosis based on host reaction to the virus inoculation indicate that the tobamovirus infecting lisianthus in Taiwan is an isolate of ToMV.