Pollen-mediated Gene Flow in Camelina sativa (L.) Crantz

Camelina sativa (L.) Crantz is a biofuel crop with application on the Great Western Plains of North America that is being developed using genetic engineering. Before release of genetically engineered cultivars, the potential for pollen-mediated gene flow (PMGF) needs to be assessed to determine if they can coexist with conventional cultivars without causing market harm. Medium-scale field experiments (40-m diameter) were conducted in 2011 and 2012 to quantify PMGF using a seed-expressed florescent marker and bar gene that confers resistance to glufosinate [2-amino-4-(hydroxymethylphosphinyl) butanoic acid] in Alberta, Canada. More than 17 million seeds were screened to quantify outcrossing. Pollen-mediated gene flow best fit an exponential decay model in which the highest average PMGF (0.78%) occurred adjacent to the donor crop and rapidly declined to 0.09% by 20 m. Pollen-mediated gene flow was leptokurtic, with a 50% reduction in gene flow 1.5 m from the pollen source. No directional trends were detected, suggesting wind dispersal was not influencing experimental results. The risk of PMGF at longer distances is minimal, but not zero, in this primarily self-pollinating species.