Evaluation of Pollen-Mediated Gene Flow from Purple-Colored Maize Line during Co-Cultivation with Yellow-Grain Maize Lines

Abstract

In this paper, we consider the pollen-mediated gene flow of purple-colored maize lines during co-cultivation with yellow-grain pollen-recipient maize lines. We analyze the factors influencing pollen dispersion: wind (speed and direction), distance, the synchrony of the pollen donor and receptor flowering. It was established that the maximum percentage of crosses in maize lines with the same flowering dates was recorded at the distance of 1–4 m from the donor plant. The percentage of crosses decreased by a factor of 5 with an increase in the distance to 10 m. At a distance of 40 m from the donor plant, the percentage of hybrid grains among the freely pollinated grains of the recipient plant fell by a factor of 12.5. At close distances (1–4 m), hybrid grains on the cobs of the recipient lines were observed 4 times longer in the line with earlier flowering periods or in the line with the same flowering times, but with a sharper angle of leaves. According to our experimental data, at a distance of 10 m from the maize of a pollen donor, the guaranteed does not exceed the Russian threshold of 0.9% of the presence of GMO products in food (yield). The analysis of experiments on maize spreading with pollen in Volga region of Russia provides evidence-based recommendations for safe co-cultivation of non-GM and GM varieties and maize lines at the distance 10 m.