Risk assessment of transgene introgression from genetically modified soybean into its wild relatives

Abstract

Abstract Background: Crop-wild hybridization has generated great concerns since gene flow can be an avenue for transgene escape. However, a rather limited number of studies on risk assessment regarding the dispersion of transgenes from GM soybean to its wild relative populations have been conducted before. Results: The results of the 3-year experiment demonstrated that F1, F2 and F3 had lower seed germination, higher pod and seed production than GM soybeans, and the seed productivity of hybrids (especially F2 and F3) were close to those of wild soybean. Furthermore, the foreign protein was stably expressed in F1, F2 and F3 EPSPS positive plants, conferring to hybrids herbicide tolerance. However, despite being stably inherited, neither the presence of the EPSPS transgene nor the number of its copies does affect the detected hybrid vigor, since no difference is observed in agronomic measurements between hybrids that are glyphosate sensitive or resistant, homozygous or heterozygous for the transgene. While EPSPS genes had little effect on crop growth and reproduction, hybridization between GM soybean to wild soybean may have more impact on hybrid growth and fecundity, this increase in biomass and yield conferring a potential competition benefit to hybrids. Conclusions: Hybrids between GM soybean and wild soybean had similar germination characteristics and seed productivity as wild parent, such characteristics acquired by gene flow have the potential to promote the adaptability of hybrids and may increase the possibility of dispersal of transgenes through seed systems.