Location: Floral and Nursery Plants ResearchTitle: A 2014 nationwide survey of the distribution of Soybean mosaic virus (SMV), Soybean yellow mottle mosaic virus (SYMMV) and Soybean yellow common mosaic virus (SYCMV) major viruses in South Korean soybean fields, and changes Author
|Li, Meijia - Chungnam National University|
|Seo, Eun-young - Chungnam National University|
|Cho, Seunghee - Chungnam National University|
|Kim, Jung-kyu - Chungnam National University|
|Chung, Jin-soo - Chungnam National University|
|Lim, Hyo-jin - Chungnam National University|
|Gotoh, Takafumi - Kyushu University|
|Lim, Hyoun-sub - Chungnam National University|
Submitted to: Journal of Faculty of Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/19/2015
Publication Date: 10/13/2015
Citation: Li, M., Seo, E., Cho, S., Kim, J., Chung, J., Lim, H., Gotoh, T., Hammond, J., Lim, H. 2015. A 2014 nationwide survey of the distribution of Soybean mosaic virus (SMV), Soybean yellow mottle mosaic virus (SYMMV) and Soybean yellow common mosaic virus (SYCMV) major viruses in South Korean soybean fields, and changes. Journal of Faculty of Agriculture. 60:339-347.
Interpretive Summary: Virus infection has adverse effects on yield and quality in many crop types, and transmission and dispersal of some viruses may occur through infected seed. In Korea, a survey to determine the distribution of three viruses affecting soybeans was carried out in 2014, and compared to results from 2012. Soybean yellow common mosaic virus and Soybean yellow mottle mosaic virus were only discovered over the past few years, whereas the third (Soybean mosaic virus) is prevalent in soybeans worldwide. Although only recently discovered, Soybean yellow mottle mosaic virus was the most commonly detected virus. Interactions between the viruses in mixed infections were also examined, and levels of Soybean yellow mottle mosaic virus found to increase significantly in mixed infections with Soybean mosaic virus. The geographical distribution of all three viruses in 2014 was similar to what was observed in 2012, but there were differences in the type of Soybean mosaic virus strains across all regions surveyed. The reasons for this change are not clear, as farmer-saved seed is presumed to be the main source of infection within the crop. These results will be useful to extension agents to educate farmers about the value of using virus-free seed to establish the crop.
Technical Abstract: In 2014 symptomatic soybean samples were collected throughout Korea, and were tested for the most important soybean viruses found in Korea, namely Soybean mosaic virus (SMV), Soybean yellow common mosaic virus (SYCMV), and Soybean yellow mottle mosaic virus (SYMMV). SYMMV was most commonly detected, followed by SMV. Only a few samples were found to be infected by SYCMV; of these, three samples were positive for double infection of SYMMV and SYCMV. Phylogenetic analysis of HC-Pro of the SMV isolates collected in 2014 from the eight provinces of Korea showed that most isolates were distinct from the most common Korean isolate detected in 2012, but related to other Korean, Chinese and North American isolates. No isolates varying in HC-Pro amino acid residues implicated in efficiency of RNA silencing suppression activity were detected in 2014. Phylogenetic analysis of ORF1 of both 2012 and 2014 SYCMV isolates showed differentiation into three subgroups. However, the geographical distribution of all three viruses in 2014 was essentially the same as observed in 2012. Quantitative real time PCR data also indicated a similar pattern of dual infected viruses occurrence as existed in 2012. Results showed SMV/SYMMV double infection RNA accumulation was not changed as much as SYMMV/SYCMV double infection. However, between double infection SMV/SYMMV, SYMMV RNA accumulation level rises about 1341 times more than SMV, and SYCMV RNA accumulation level decline a little compare with SYMMV. In summary, the 2014 survey showed that SMV and SYMMV are still the most prevalent soybean viruses in Korea, and all three viruses were still dispersed in the same areas where they were detected in 2012, although with an apparent shift towards SMV Group I isolates compared to 2012. The reason for the shift in SMV isolates across all Korean provinces is not clear, as seed transmission through farmer-saved seed is presumed to be the main source of infection within the crop.