Abstract
In the present study, a 3-year pot experiment was conducted to
investigate the agronomic performance of different generation hybrids
between genetically modified (GM) soybean and wild soybeans as well as
inheritance of the CP4 -EPSPS transgene and its effects on
the seed germination rate, aboveground biomass, and fecundity in
F1, F2 and F3populations. Furthermore, the expression of transgenic proteins in
various hybrids was also investigated.
The results showed that the F1 hybrids had higher
germination rates (weaker dormancy) and lower pod and seed numbers than
the wild soybean. The F2 and F3populations also had higher germination rates than wild soybean, but the
F2 and F3 populations had nearly the
same biomass, pod and seed yield as their maternal parents across the
whole life cycle; while the seed germination rate, biomass, and
fecundity were similar in EPSPS negative, homozygous and heterozygous
plants of F2 and F3 populations.
Furthermore, EPSPS proteins were detectable in F1,
F2 and F3 progeny at different growth
stages.
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, especially the seed
germination rate and fecundity. F1, F2and F3 had lower seed germination but higher pod and
seed production than GM soybeans, and these parameters were close to
those of wild soybean. 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.