Pollen-mediated gene flow in flax at various locations and years (a) EdRS, 2006; (b) EIRS, 2006; (c) EdRS, 2007; and (d) EIRS, 2007. The triangle indicates the distance, in which 50% (O50) reduction in the frequency of gene flow and the arrow indicates the distance in which 90% (O90) reduction in gene flow from the pollen source (m).