台灣澎湖地區感染香瓜茄（Solanum muricatum）之番茄嵌紋病毒（Tomato mosaic virus）鑑定與發生調查

Pepino (Solanum muricatum) is a kind of solanaceous vegetables. We have isolated a virus from the cultivated pepino plants in Penghu, an archipelago situates in Taiwan Strait. The virus isolate, designated as ToMV-Penghu, was obtained after three successive local-lesion isolations on Chenopodium quinoa. By mechanical inoculation, ToMV-Penghu could infect Tetragonia tetragonioides, Chenopodium amaranticolor, C. quinoa, C. murale, Gomphrena globosa, Spinacia oleracea, Catharanthus roseus, Lactuca sativa, Zinnia violacea, Basella alba, Cardamine flexuosa, Cucurbita pepo, Lagenaria siceraria, Sesamum indicum, Antirrhinum majus, Capsicum annuum, Nicotiana benthamiana, N. tabacum, Solanum lycopersicum, S. melongena, S. muricatum, S. nigrum, and S. tuberosum in the experiment. Rod-shaped particles with the size of 300-310 x 18-20 nm can be observed in purified preparation of ToMV-Penghu by electron microscopy. The relative molecular weight of viral coat protein was estimated as about 19kDa by SDS-PAGE. The protein was applied to prepare the specific rabbit polyclonal antiserum against ToMV-Penghu. By serological reactions in SDS-immunodiffusion, enzyme-linked immunosorbent analysis (ELISA) and western blot, the ToMV-Penghu was identified as a species of Tobamovirus. For further identification, a pair of primers (TMVmpf / TMV3nr) spanning the tobamovirus coat protein (CP) gene were adopted for reverse transcription polymerase chain reaction (RT-PCR) and that resulted in producing an 800-bp DNA fragment. After cloning and sequencing, this nucleotide sequence was deposited in the GenBank database as Accession No. JQ085379. Comparing with the CP gene of other tobamoviruses in the Genebank by nucleotide sequence alignment, JQ085379 shared more than 99% of identities with tested ToMV isolates but only 75% with the TMV isolates. Therefore, ToMV-Penghu is identified as an isolate of Tomato mosaic virus (ToMV) and belongs to Clade I genotype as tested by phylogenetic analysis. The incidence of ToMV in pepino plants was surveyed with specific antibody against ToMV-Penghu by ELISA. ToMV could be commonly detected in plants and fruits of economically cultivated pepino collected in Penghu but not in pepino twigs or seeds collected in Taiwan. This is the first report of a ToMV infecting pepino plants in Taiwan.