Evaluating the risk of living modified organisms on the natural ecosystem by analyzing the overwintering potential of four major species imported into Korea

Background: Living modified organisms (LMOs) imported into Korea may pose various risks to the domestic natural ecosystem, depending on their seed survival capacity and proliferation potential.In this study, we investigated seed germination and dormancy rates under controlled low temperatures for 12 weeks.In addition, we assessed the overwintering potential of seeds buried at 10 cm soil depth over 48 weeks using non-transgenic seeds of four major LMOs imported into Korea.Results: Brassica napus L. seeds exhibited superior germination and dormancy rates compared to Glycine max (L.) Merr., Zea mays L., and Gossypium hirsutum L. seeds when subjected to incubation at low temperatures (-5C, -1C, and 5C).Seed germination was exclusively recorded for B. napus seeds in the field, which reflects the winter environment, for up to 8 weeks after burial.Seeds of both B. napus and Z. mays remained dormant in the soil for up to 4 weeks after burial; however, G. max and G. hirsutum seeds did not remain dormant.Germination rates were higher when the seeds were placed in seed bags and buried, whereas dormancy rates were higher when the seeds were buried without seed bags.Conclusions: These results suggest that B. napus could have a higher invasive potential than other plant species, which may affect its survival and spread, ultimately posing a greater threat to the ecosystem.This study provides valuable insights into the immediate need for establishing risk assessments and safety management measures for LMOs (specifically B. napus).