Movement and Persistence of Genes in the Environment

Image of feral oilseed rape growing alongside a new field of oilseed rapeThe movements of genes and organisms over the landscape are natural processes that came to public attention in the assessment of GM crops. Issues on gene and seed movement go beyond the GM debate, and indeed, the major current research here on geneflow uses non-GM markers. The group combines statistical, molecular, genetic, mathematical and ecological skills to investigate the movement of genetic material and its consequences. It maintains large study areas in Tayside and in England in which it tracks the occurrence and persistence of volunteers, ferals and wild relatives.

Research projects

Research has developed in this topic for more than ten years through a series of projects funded from Europe, the UK and Scotland and from the research councils in collaboration with universities. Our contributions over this period include:

  • taking the UK lead on geneflow and persistence of GM traits among crops and their volunteer weeds and ferals
  • advising international (WTO, EU) and national (UK, Scotland, EU member states) bodies on gene flow, GM persistence and co-existence of GM and non-GM crops.
  • pioneering the study of long-range, low-frequency cross pollination in real agricultural landscapes
  • advising farming, policy and the agricultural industry on the management of fields to reduce GM persistence
  • maintaining the longest running and most extensive study of feral oilseed rape in Europe, showing ferals persist over time at low frequency in the landscape
  • compiling the most detailed and comprehensive data bank on geneflow and GM impacts.

The main projects and analysis in 2007-2009:

  • persistence of GM herbicide tolerant oilseed rape at GM Farm Scale Evaluation sites
  • low frequency geneflow and persistence measured by molecular, biochemical and statistical approaches
  • individual-based plant life cycle models linking inputs and outputs through data-mining technology with the Josef Stefan Institute, Slovenia (Marko Debeljak and Saso Dzeroski)
  • use of the high erucic acid marker in oilseed rape to measure cross pollination in the landscape
  • collation of European data on geneflow and GM impacts in maize, beet and oilseed rape in the project SIGMEA.

The main coordinators and contacts for this area of research are Geoff Squire and Graham Begg. Other contributions from Agroecology include Pete Iannetta (protein-based detection, seed persistence), Gill Banks (ferals) and Linda Ford (technical, sample processing), and from other groups in SCRI, Danny Cullen (DNA methodologies), Gavin Ramsay (genetics, landscape processes), Charlie Scrimgeour (chemistry) and Jim McNicol (statistics).

The group co-ordinates major projects in the UK carried out jointly with Rothamsted Research and the Centre for Ecology and Hydrology, NIAB, ADAS and CSL. In 2004, the group took on a major role in the 45-partner SIGMEA project, collating and analysing experimental findings across Europe on gene flow, persistence and GM impacts in beet, maize, oilseed rape and other crops. A major tranche of papers on findings from experimental work 2002-2007 is in preparation for peer-reviewed journals.

 Map of an oilseed rape field showing the gradient top to bottom of raised % erucic acid Image (right): Map of an oilseed rape field showing the gradient top to bottom of raised % erucic acid following cross pollination from a high erucic field located beyond the top end of the field; red shows erucic acid concentrations of 0.1%, blue 0.015%; all values are well below the EU threshold for high erucic in low erucic oilseed rape of 2%.


Papers and reports

Peer reviewed journal papers

Squire GR, Breckling B, Dietz Pfeilstetter A, Jorgensen RB, Lecomnte J, Pivard S, Reuter H, Young MW. 2010. Status of feral oilseed rape in Europe: its minor role as a GM impurity and its potental as a reservoir of GM persistence. Environmental Science and Pollution Research (doi:10.1007/s11356-010-0376-1)

Bagavathiannan MV, Gulden RH, Begg GS, Van Acker RC. 2010. The demography of feral alfalfa (Medicago sativa L.) populations occurring in roadside habitats in Southern Manitoba, Canada: implications for novel trait confinement. Environmental Science and Pollution Research (doi:10.1007/s11356-010-0330-2)

Cullen, D.W., Squire, G.R., McNicol, J.W, Jacobs, H.H., Osborne, J.L., Ford, L., Ramsay, G., Scrimgeour, C., Young, M.W. 2008. Development and validation of gas chromatography and real-time quantitative PCR for the quantification of landscape-scale gene flow from varieties of high erucic (HEAR) oilseed rape. Journal of the Science of Food and Agriculture 88(13), 2253-2264. Published online: Sep 8 2008 11:30 am (doi: 10.1002/jsfa.3340).

Begg, G.S., Elliott, M.J., Cullen, D.W., Iannetta, P.M.M., Squire, G.R. 2008. Heterogeneity in the distribution of genetically modified and conventional oilseed rape within fields and seed lots. Transgenic Research 17, 805-816 (doi:10.1007/s11248-008-9166-7).

Begg, G.S., Cullen, D.C., Iannetta, P.M. and Squire, G.R. 2007. Sources of uncertainty in the quantification of genetically modified oilseed rape contamination in seed lots. Transgenic Research 16, 51-63.

Begg, G.S., Hockaday, S., McNicol, J.W., Askew, M. and Squire, G.R. 2006. Modelling the persistence of volunteer oilseed rape (Brassica napus). Ecological Modelling 198, 195-207. 

Marshall, B., Dunlop, G., Ramsay, G., Squire, G.R. 2000. Temperature-dependent germination traits in oilseed rape associated with 5’-anchored simple sequence repeat PCR polymorphisms. Journal of Experimental Botany 51, 2075-2084.

Squire, G.R. 1999. Temperature and heterogeneity of emergence time in oilseed rape. Annals of Applied Biology 135, 439-447.

Squire, G.R., Marshall, B., Dunlop, G., Wright, G. 1997. Genetic basis of rate-temperature characteristics for germination in oilseed rape. Journal of Experimental Botany 48, 869-875.

Marshall, B., Squire, G.R. 1996. Non-linearity in the rate-temperature relations of germination in oilseed rape. Journal of Experimental Botany 302, 1369-1375.

Timmons, A.M., Charters, Y., Crawford, J.W., Burn, D., Scott, S., Dubbels, S.J., Wilson, N.J., Robertson, A., O'Brien, E.T., Squire, G.R., Wilkinson, M.J. 1996. Risks from transgenic crops. Nature 380, 487.


Peer reviewed reports to government

Squire, G.R., Hawes, C., Bohan, D.A., Brooks, D.R., Champion, G.T., Firbank, L.G., Haughton, A.J., Heard, M.S., May, M.J., Perry, J.N., Young, M.W. 2005. Biodiversity effects of the management associated with GM cropping systems in the UK. Defra, London.

Ramsay, G., Thompson, C.E., Squire, G.R. 2003. Quantifying landscape-scale gene flow in oilseed rape. Final report on Project RG0216, 48 pages. Defra, London. PDF file: 579 kb

Squire, G.R., Begg, G.S., Askew, M. 2003. The potential for oilseed rape feral (volunteer) weeds to cause impurities in later oilseed rape crops. Defra final report on Project RG0114, 27 pages. PDF file: 154 kb.

Charters, Y.M., Robertson, A., Squire, G.R. 1999. Investigation of feral oilseed rape populations. Genetically modified organisms research report (No. 12). Department of the Environment, Transport and the Regions, London, 93 pages. (Available in hard copy from Defra Publications, Admail 6000, London SW1A 2XX. Email: or


Conference proceedings and SCRI annual reports (examples)

Crawford, J.W., Squire, G.R., Burn, D. 1999. Modelling the spread of herbicide resistance in oilseed rape. Proceedings of the DoE workshop on the Impact of transgenes on the environment, December 1995. Department of the Environment, Transport and the Regions. Now Defra, London.

Squire, G.R., Crawford, J., Ramsay, G.H., Thompson, C., Bown, J. 1999 Geneflow at the landscape level. In Geneflow in agriculture: relevance for transgenic crops. BCPC Symposium Proceedings No. 72, 57-64. (Keele Conference)

Thompson, C., Squire, G.R., Mackay, G., Bradshaw, J., Crawford, J., Ramsay, G. 1999. Regional patterns of geneflow and its consequences for GM oilseed rape. BCPC Symposium Proceedings No. 72, 95-100. (Keele Conference)

Squire, G.R., Augustin, N., Bown, J., Crawford, J.W., Dunlop, G., Graham, J., Hillman, J.R., Marshall, B., Marshall, D., Ramsay, G., Robinson, D.J., Russell, J., Thompson, C., Wright, G. 2000. Gene flow in the environment - genetic pollution? SCRI Annual Report 1998/99, 45-54.

Robinson, D.J., Davies, H.V., Birch, A.N.E., Wilson, T.M.A., Kerby, N.W., Squire, G.R., Hillman, J.R. 1998. Development, release and regulation of GM crops. SCRI Annual Report 1997/98, 44-53.


Study areas and GIS data sets

As part of our work on regional gene movement, we are prepared to share our GIS data sets with collaborators.

Young, M.W., Banks, G., Squire, G.R. Oilseed rape fields and ferals in the Tayside Study Area. Completed: 2005. Agroecology Data Archive, SCRI, Dundee DD2 5DA, UK.

The main data set gives locations and population data on ferals and oilseed rape fields in a 500 km2 mainly rural area in Angus in 1993, 1994, 1995, 1996 and 2004; additional years in smaller areas. Collection of data began in 1993 by SCRI staff Y.Charters and E.O'Brien and is described in the Defra report by Charters et al . (1999). GIS data set compiled and completed 2004-05 by authors. Collaborators to date - Josef Stefan Institute, Slovenia; University of Bremen, Germany; University Paris 11, Orsay, France.

Young, M.W., Brown, L., Dawson, G., Squire, G.R. Field pattern and land use in the Fife study area. Completed 2006. Agroecology Data Archive, SCRI Dundee DD2 5DA, UK.

The main data set gives field polygons (and crop types in 2004), and land use in other polygons (for example, as a base for estimating gene movement in and out of fields); a joint exercise between SCRI and Scottish Agronomy (G. Dawson) funded by the Scottish Executive. Collaborators to date - Cetiom, France; Rothamsted Research, UK; Cranfield, UK; Central Science Laboratory, UK.

Image of the Tayside Study Area

Figure: Example of a 15 x 10 km section of the Tayside Study Area showing cumulative areas over four consecutive years occupied by winter (yellow) and spring (brown) oilseed rape fields and the location of feral populations (coloured dots). © Crown copyright. All rights reserved. SCRI 100010972 2005. From the Defra report by Squire et al. (2005).