Environmental Biosafety Research

Research Article

Monitoring the escape of transgenic oilseed rape around Japanese ports and roadsides

Hikaru Sajia1, Nobuyoshi Nakajimaa2, Mitsuko Aonoa1, Masanori Tamaokia2, Akihiro Kuboa1, Seiji Wakiyamaa3, Yoriko Hatasea3 and Masato Nagatsua3

a1  Environmental Biology Division, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, 305-8506, Japan

a2  Biodiversity Conservation Research Project, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, 305-8506, Japan

a3  Japan Wildlife Research Center, 3-10-10 Shitaya, Taito-Ku, Tokyo, 110-8676, Japan


An investigation was carried out to monitor the escape and spread of oilseed rape (Brassica napus) transgenic plants and the introgression of transgenes to its closely related feral species in Japan. We screened a total of about 7500 feral B. napus, 300 B. rapa, and 5800 B. juncea seedlings from maternal plants in 143 locations at several ports, roadsides, and riverbanks. The presence of glufosinate-resistance or glyphosate-resistance transgenes in these seedlings was confirmed by means of herbicide treatments and also immunochemical and DNA analyses. B. napus plants with herbicide-resistant transgenic seeds were found at five of six major ports and along two of four sampled roadsides in the Kanto District. Transgenic oilseed rape plants have not been commercially cultivated in Japan, suggesting that the transgenes would probably have come from imported transgenic seeds that were spilled during transportation to oilseed processing facilities. No transgenes were detected in seeds collected from B. napus plants growing along riverbanks in the Kanto District or in seeds from closely related species (B. rapa and B. juncea). To our knowledge, this is the first published example of feral, transgenic populations occurring in a nation where the transgenic crop has not been cultivated commercially.

(Online publication June 22 2006)

Key Words:

  • Brassica ;
  • establishment;
  • glufosinate;
  • glyphosate;
  • herbicide;
  • introgression;
  • transgenic plant


c1 hsaji@nies.go.jp