Hourly pollen dispersal of Camelina sativa (L.) Crantz under different weather conditions and mitigation of wind-blown pollen dispersal using maize barrier

Abstract

The potential for introgression of genetically engineered (GE) Camelina sativa (L.) Crantz alleles into conventional crop or closely-related population under field conditions has raised the ecological concerns. Knowledge about the effect of factors associated with pollen-mediated gene flow is necessary for developing strategies for biocontainment and mitigating transgene flow from GE C. sativa to non-GE crops. In this study, in the center of C. sativa source, pollen first observed was between 8:00 and 9:00 o’clock (about 4 pollen m−3 h–1) and peaked between 11:00 and 13:00 (ranges: 116–240 pollen m−3 h–1) followed by a decrease to lower levels by 17:00 during the flowering period that lasted 33–37 days. Camelina sativa pollen concentration out of the pollen source was affected by sampling date and time, sampling distance, weather condition, but not sampling direction and sizes of pollen source (Ø = 10 or 20 m). Mean pollen concentrations over 10 h consistently decreased with distance at four cardinal directions from the center of pollen source. Directional wind did not significantly affect C. sativa pollen dispersal. The predicted pollen concentration at 10 m (< 2 pollen m–3 h–1) using the developed model supports a minimum isolation distance of 10 m between C. sativa crops to maintain the gene flow rate < 0.01 %. Furthermore, a maize (Zea mays L.) barrier rows was tested to be an effective tool for reducing C. sativa pollen flow in research scale planting. The results demonstrated that long-distance C. sativa pollen dispersal is unlike. The new information in this study will be useful for predicting pollen-mediated transgene flow in GE C. sativa, providing coexistence strategies between GE and non-GE C. sativa, and thus contribute to ecological risk assessments of GE C. sativa and other crops.