High maize barrier prevents maize pollen transfer in mixed crops

Abstract

BACKGROUND: There is no scientifically-based assessment for the safety during co-cultivation of genetically modified and ordinary maize plants in Russia. The influence of the barrier from high maize plants for pollen-mediated gene flow in the 2020 field experiment (South-East of the European part of Russia, Saratov region) was evaluated. MATERIALS AND METHODS: We used the high (2,152,90 m) maize hybrids (Kaz LK 178 and ES Regain) as a barrier for pollen-madiated gene flow from pollen donor (Purple Saratovskaya) with purple grain to recipient (Bursting Corn) maize line with yellow grain. RESULTS: The analysis of the ears of the recipient maize line showed that not a single purple grain was found on them. It was found that in the presence of a barrier zone with a width of 315 m (depending on the direction), crossing in recipient maize line in all directions from the donor is completely excluded. CONCLUSIONS: It was established, for the first time, that the barrier from high maize hybrid plants completely excludes over-pollination between donor and Bursting Corn, recipient maize plants with different flowering time. In the study of barrier plants as pollen recipients, it was found that the percentage of crosses on the cob of barrier plants ranged from 0.1 to 7.1%. The number of crosses exceeding 0.9% is observed mainly in the ES Regain variety at close (15 m) distances from the donor, regardless of the prevailing wind direction. Based on the results of model experiments, it can be recommended to use a barrier for corn pollen from tall maize plants and maize varieties with different flowering periods to exclude uncontrolled over-pollination of maize varieties in the South-East of the European part of Russia conditions.