This study aimed to improve knowledge of gene flow in oilseed rape to
enable better prediction of cross-pollination on the landscape-scale.
To estimate maximum cross-pollination, small groups of male-sterile plants
were placed over a wide area within and around a typical oilseed rape
region in E Scotland. The patterns of decline from the nearest source
indicated that segregation by distance is an inefficient means of reducing
cross-pollination. No upper limit to gene flow in oilseed rape was found,
despite testing long distances. Estimates of cross-pollination into male-sterile
oilseed rape over-estimated that into male-fertile plants by about one
order of magnitude. A further reduction was encountered when the recipient
plants were part of a large population of male-fertile plants. Understanding
the spatial patterns of gene flow and predicting it in new situations
depends on an understanding of the vectors involved. It was demonstrated
that airborne pollen is relatively ineffective, and that much of the pollination
taking place over a few km is vectored by bees and other insects. Predictions
were made of the possible levels of gene flow in realistic situations
over widely differing distances, and into different types of oilseed rape
population.
Anon. [Ramsay, G., and Hillman, J.R.] (2000) Scottish Crop Research
Institute Memorandum on Gene Flow and SCRI Research. Annex 1. Eighth
Report of the House of Commons Select Committee on Agriculture. 'Genetically
Modified Organisms and Seed Segregation'. ISBN 0 10 257400 6.
(www.parliament.the-stationery-office.co.uk/pa/cm199900/cmselect/cmagric/812/812ap02.htm)
Ramsay, G, Thompson, CE, Neilson, SJ, and Mackay, G. (1999) Honeybees
as vectors of GM oilseed rape pollen. 1999 BCPC Symposium Proceedings
No 72. Gene Flow and Agriculture: Relevance for Transgenic Crops. pp.
209-214.
Squire, G.R., Augustin, N., Bown, J., Crawford, J.C., Dunlop, G., Graham,
J., Hillman, J.R., Marshall, B., Marshall, D., Ramsay, G., Robinson,
D.J., Russell, J., Thompson, C., and Wright, G. (1999) Gene flow in
the environment: genetic pollution? SCRI Annual Report 1998/1999, pp.
45-54.
http://wwwexternal.scri.sari.ac.uk/SCRI/upload/annualreportdocuments/99Indiv/04GenPol.pdf
Squire, G.R., Begg, B., Crawford, J., Gordon, S., Hawes, C., Johnstone,
C., Marshall, B., Ramsay, G., Thompson, C., Wright, G., and Young, M..
(2003) Outcrossing among crops and feral descendents - geneflow. SCRI
Annual Report 2001/2002. pp 176-180.
http://wwwexternal.scri.sari.ac.uk/SCRI/upload/annualreportdocuments/02Indiv/33OutCr.pdf
Squire, G, Crawford, JW, Ramsay, G, Thompson, CE, and Bown, J. (1999)
Gene flow at the landscape level. 1999 BCPC Symposium Proceedings No
72. Gene Flow and Agriculture: Relevance for Transgenic Crops. pp. 57-64.
Thompson, CE, Squire, G, Mackay, GR, Bradshaw, Crawford, J, and Ramsay,
G. (1999) Regional patterns of gene flow and its consequence for GM
oilseed rape. 1999 BCPC Symposium Proceedings No 72. Gene Flow and Agriculture:
Relevance for Transgenic Crops. pp. 95-100.
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