Dual infections of ToMV and TYLCV, or ToMV and ToCV, detected in tomato fields located in Chungchungnam-Do in 2017

Authors: CHOI, GO-WOON - Chungnam National University; KIM, BORAM - Chungnam National University; JU, HYEKYOUNG - Chungnam National University; SEO, EUN-YOUNG - Chungnam National University; KIM, JUNG-KYU - Chungnam National University; PARK, JONGSEOK - Chungnam National University; Hammond, John; LIM, HYOUN-SUB - Chungnam National University

Submitted to: Korean Journal of Agricultural Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/18/2018
Publication Date: 3/3/2018
Citation: Choi, G., Kim, B., Ju, H., Seo, E., Kim, J., Park, J., Hammond, J., Lim, H. 2018. Dual infections of ToMV and TYLCV, or ToMV and ToCV, detected in tomato fields located in Chungchungnam-Do in 2017. Korean Journal of Agricultural Science. 45(1):38-42. https://doi.org/10.7744/kjoas.20180008.
DOI: https://doi.org/10.7744/kjoas.20180008

Interpretive Summary: Tomatoes are increasing demand in Korea as people try to eat a healthier diet. However, pressure of whitefly-transmitted virus diseases has also increased as a result of environmental variability. Samples displaying virus-like symptoms were collected from the main Korean tomato producing areas and assayed for the two primary whitefly-transmitted viruses affecting tomato (Tomato yellow leaf curl virus, and Tomato chlorosis virus), and also for two other major viruses affecting tomato (the mechanically-transmitted Tomato mosaic virus, and the thrips-transmitted Tomato spotted wilt virus). Most of the samples found to be infected with Tomato mosaic virus were also infected with either Tomato yellow leaf curl virus or Tomato chlorosis virus. Determination of partial sequences of isolates of Tomato yellow leaf curl virus and Tomato chlorosis virus revealed high similarity to isolates reported in other countries; these viruses may have been introduced into Korea on wind-blown whiteflies, or possibly in imported seeds. The occurrence of these viruses in mixed infections with Tomato mosaic virus suggests increased crop damage, and the necessity for more rigorous control measures to protect crop yields.

Technical Abstract: Demand for tomatoes has been increasing every year as people desire more healthful food. In Korea tomatoes are mainly grown in Chungnam, Chunnam and Kyungnam provinces. Recently, reports of whitefly-transmitted viral diseases have increased due to newly emerging whitefly pressures caused by climate change in Korea. Specifically, in 2017 the main tomato growing areas, Buyeo and Nonsan in Chungnam, showed damage typical of viral infection; therefore we investigated viral diseases in these areas. We collected samples with virus-like symptoms and revealed that not only whitefly transmitted Tomato yellow leaf curl virus (TYLCV) and Tomato chlorosis virus (ToCV) were detected, but also Tomato mosaic virus (ToMV) and Tomato spotted wilt virus (TSWV). ToMV-infected samples were mostly co-infected with either TYLCV or ToCV. According to CP sequence of each virus, 100% identities were shown to Mexico/ABG73017.1 (TYLCV), Greece/CDG34553.1 (ToCV), China/AKN79752 (TSWV), and Australia/NP078449.1 (ToMV). Based on sequence data we presumed that these tomato infecting viruses were transmitted through introduced insects and seed from neighboring countries.