Figure 1
Design of field gene flow experiment. A modified Nelder wheel design was used evaluate the gene flow of hybrid GFP plants. Three plant types were used in the experiment: male sterile N. tabacum ‘MS TN 90’ were pollen ‘receptor’ plants, hybrid GFP was fluorescently tagged to enable gene flow tracking, and N. tabacum type SN 2108 was used as a pollen donor to assure pollen flow was occurring in the field by seed set on MS TN 90 and to test for female sterility of the hybrid GFP plants. A center pollen source patch contained 50 alternating hybrid GFP and fertile SN 2108 plants, spaced approximately 1 m apart. Sixteen 1 m2 blocks of male sterile MS TN 90 pollen receptor plants were placed at 9, 23, 38, and 54 m distances from the center and were used to detect pollen via seed formation. Each MS TN 90 plot was 22.5° relative to the adjacent plot as viewed from the center. A honeybee hive was placed at the center of the field site to vector pollen.