Fitness changes in wild soybean caused by gene flow from genetically modified soybean

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 populations of its wild relatives have been previously conducted.

Results: The results of the 3-year experiment demonstrated that hybrids between GM soybeans and wild soybean had lower seed germination and higher seed productivity than GM soybean. Both of these features of hybrid (especially F₂ and F₃) were similar to those of wild soybean. Furthermore, the foreign protein was stably expressed in hybrid EPSPS positive plants; however, no difference was observed in agronomic measurements between hybrids that are glyphosate sensitive or resistant, homozygous or heterozygous for the transgene, indicating that the presence of the EPSPS transgene does not affect the vigor of hybrid. In contrast, hybridization between GM soybean and wild soybean may have more impact on hybrid growth and fecundity, this increase in biomass and yield confers a potential competition benefit to hybrids.

Conclusions: Gene flow from GM soybean to wild soybean has the potential to promote the adaptability of hybrids and may increase the possibility of dispersal of transgenes in wild soybean relatives.

Keywords: Ecological risk; Gene flow; Hybrid fitness; Transgenic soybean.