First Report of Tomato spotted wilt virus in Eustoma grandiflorum in Korea

Abstract

HomePlant DiseaseVol. 101, No. 3First Report of Tomato spotted wilt virus in Eustoma grandiflorum in Korea Previous DISEASE NOTES OPENOpen Access licenseFirst Report of Tomato spotted wilt virus in Eustoma grandiflorum in KoreaJ. Y. Yoon, G. S. Choi, and S. K. ChoiJ. Y. YoonSearch for more papers by this author, G. S. ChoiSearch for more papers by this author, and S. K. ChoiSearch for more papers by this authorAffiliationsAuthors and Affiliations J. Y. Yoon G. S. Choi S. K. Choi , Virology Unit, Department of Horticultural and Herbal Environment, National Institute of Horticultural and Herbal Science, RDA, Wanju, Jeollabuk-Do, 55365, Republic of Korea. Published Online:13 Dec 2016https://doi.org/10.1094/PDIS-10-16-1514-PDNAboutSectionsSupplemental ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat Tomato spotted wilt virus (TSWV) (genus Tospovirus, family Bunyaviridae) was first reported in Korea in 2004 (Choi et al. 2004) and the virus is currently widespread in the country, infecting pepper, tomato, potato, and wild plant species (Choi et al. 2014). TSWV is transmitted by at least 11 species of thrips (e.g., Frankliniella occidentalis), one species of Ceratothripoides, and one species of Scirtothrips. Transmission can also be archived through infected plant sap. Lisianthus (Eustoma grandiflorum) is an herbaceous annual and an emerging flower for weddings, producing eight million cutting flowers in 2014 in Korea. In January 2016, virus-like symptoms including mosaic and wilting followed by necrosis on leaves and branch were observed in lisianthus plants in a greenhouse in Tae-An-gun, Korea. Approximately 10% of lisianthus plants (about 3,000 plants) in the greenhouse showed virus-like foliar symptoms, based on visual estimates. To identify a causal virus, four symptomatic leaf samples of lisianthus plants were analyzed by transmission electron microscopy (TEM) of leaf dip-preparations. Tospovirus-like particles (about 80 to 100 nm in diameter) were observed from all the samples of lisianthus plants. To confirm TEM result, the symptomatic leaf samples were further analyzed using double-antibody sandwich (DAS)-ELISA kits (Agdia, Elkhart, U.S.A.) for the presence of three lisianthus-infecting viruses, such as Bean yellow mosaic virus, Cucumber mosaic virus, and TSWV, as our preliminary survey on flowers. A positive control and a negative control (leaves of healthy a lisianthus plant) were used. DAS-ELISA clearly showed that TSWV was only detected serologically from the naturally infected lisianthus plants. The single infection of TSWV in the symptomatic lisianthus plants was further confirmed by a TSWV-Immunostrip kit (Agdia). To confirm the presence of TSWV alone, RT-PCR products were synthesized for L, M, and S RNA segments using Tospovirus-specific primers and TSWV-specific primers (Batuman et al. 2014; Choi et al. 2014). The expected fragments of 445, 868, and 777 bp were amplified and sequenced (LC191920, LC191921, LC168751). The sequences of each fragment were identical to a consensus sequence, showing 97, 98, and 99% identity with TSWV-L, M, and S RNA (KC494520, HM581941, and KC494482), respectively. These results clearly showed that the results of DAS-ELISA and the TSWV-Immunostrip kit were not due to interspecies cross-reactivity of the virus-specific antibodies. The results of sequence comparisons showed no reassortment between TSWV and another tospovirus. Taken together, a distinct TSWV isolate is the causal agent in the diseased lisianthus plants. To our knowledge, this is the first report of TSWV in lisianthus in Korea. The epidemic nature of TSWV, along with lisianthus production in Korea, warrants monitoring for TSWV in greenhouse production in Korea.