Monitoring the occurrence of genetically modified maize in Korea: A 3-year observations

The cultivation area of genetically modified (GM) crops is increasing all over the world. Currently, GM crops are not allowed to grow in Korea but have officially been allowed to import as food and feed purposes. In recent years, concerns regarding the unintentional escape of GM crops during transport and manufacturing, and the subsequent contamination of the local, non-GM plants have been raised. In this connection, monitoring was executed around grain-receiving ports and feed manufacturing plants at 31 sites in six provinces of Korea from July to September 2010-2012. We found spilled maize grains and established plants around open storage areas of ports and along transportation routes near feed-manufacturing plants. A total of 151, 191, and 21 maize plants were found in 2010, 2011, and 2012, respectively. Based on PCR analyses, 11, 35, and 5 plants were detected as GM in 2010, 2011, and 2012, respectively. Where the plants were confirmed as GM maize, we revisited the sites several times every year until the end of maize growing season. In most cases, the established maize plants found in this study were at the vegetative stage and failed to reach up to reproductive stage. Moreover, the established maize plants found during the year of 2010 and 2011 were not found at the same sites thereafter. Based on the results of this study, we conclude that, although GM maize plants could escape during transport or storage, their infestation by overwintering or pollen flow of GM maize is not likely to occur in the environment of Korea.