Unexpected Diversity of Feral Genetically Modified Oilseed Rape (Brassica napus L.) Despite a Cultivation and Import Ban in Switzerland

Abstract

Despite cultivation and seed import bans of genetically modified (GM) oilseed rape (Brassica napus L.), feral GM plants were found growing along railway lines and in port areas at four sites in Switzerland in 2011 and 2012. All GM plants were identified as glyphosate-resistant GM event GT73 (Roundup Ready, Monsanto). The most affected sites were the Rhine port of Basel and the St. Johann freight railway station in Basel. To assess the distribution and intra- and interspecific outcrossing of GM oilseed rape in more detail, we monitored these two sites in 2013. Leaves and seed pods of feral oilseed rape plants, their possible hybridization partners and putative hybrid plants were sampled in monthly intervals and analysed for the presence of transgenes by real-time PCR. Using flow cytometry, we measured DNA contents of cell nuclei to confirm putative hybrids. In total, 2787 plants were sampled. The presence of GT73 oilseed rape could be confirmed at all previously documented sampling locations and was additionally detected at one new sampling location within the Rhine port. Furthermore, we found the glufosinate-resistant GM events MS8xRF3, MS8 and RF3 (all traded as InVigor, Bayer) at five sampling locations in the Rhine port. To our knowledge, this is the first time that feral MS8xRF3, MS8 or RF3 plants were detected in Europe. Real-time PCR analyses of seeds showed outcrossing of GT73 into two non-GM oilseed rape plants, but no outcrossing of transgenes into related wild species was observed. We found no hybrids between oilseed rape and related species. GM plants most frequently occurred at unloading sites for ships, indicating that ship cargo traffic is the main entry pathway for GM oilseed rape. In the future, it will be of major interest to determine the source of GM oilseed rape seeds.

Scientific Opinion on an application by Bayer CropScience and Monsanto (EFSA‐GMO‐NL‐2009‐75) for placing on the market of genetically modified glufosinate‐ammonium‐ and glyphosate‐tolerant oilseed rape MS8 × RF3 × GT73 and subcombinations, which have not been authorised previously (i.e. MS8 × GT73 and RF3 × GT73) independently of their origin, for food and feed uses, import and processing, with the exception of isolated seed protein for food, under Regulation (EC) No 1829/2003

“…Survival of oilseed rape outside cultivation areas is possible. Demographic studies and surveys have shown the ability of oilseed rape (B. napus) to establish self-perpetuating populations outside agricultural areas, mainly in seminatural and ruderal habitats in different countries (reviewed by Devos et al, 2012;Bauer-Panskus et al, 2013;COGEM, 2013;Hecht et al, 2014;Schulze et al, 2014;Katsuta et al, 2015;Busi and Powles, 2016;Nishizawa et al, 2016). oilseed rape is generally regarded as an opportunistic species, which can take advantage of disturbed sites (e.g.…”

Spillage of Viable Seeds of Oilseed Rape along Transportation Routes: Ecological Risk Assessment and Perspectives on Management Efforts

“…Here, mixtures of OSR varieties as well as imported OSR seeds are handled. Schulze et al (2014) confirmed GM OSR spillage at such sites in Switzerland. Although import of GM OSR seeds is banned, GM OSR was found in the St. Johann railway station and the Rhine port of Basel.…”

“…These four sites were ports and railway stations on the borders to France and Italy. The feral plants probably originated from spillage of contaminated OSR seed from freight trains (Hecht et al, 2014;Schulze et al, 2014Schulze et al, , 2015. Spillage of GM OSR seeds along transportation routes was also confirmed in Japan where cultivation of GM OSR is also prohibited (Saji et al, 2005;Kawata et al, 2009;Nishizawa et al, 2009Nishizawa et al, , 2010Aono et al, 2011;Mizuguti et al, 2011), the United States (in North Dakota 80% of feral OSR proved to be GM: Schafer et al, 2011;Sagers et al, 2012) and Canada (Yoshimura et al, 2006;Knispel et al, 2008;Beckie and Warwick, 2010;Knispel and McLachlan, 2010).…”

Herbicide resistance and biodiversity: agronomic and environmental aspects of genetically modified herbicide-resistant plants

“…Seed spill can also occur outside the fields and along transport routes, potentially leading to HR feral plants that may persist over large spatial and temporal scales [101]. HR feral oilseed rape plants have been found along transport routes in the US [102], in Switzerland [103] and Japan [104], in regions where they had never been grown.…”