The 2002
In one research study, transfer
of the Bt trait from GE sunflowers to wild sunflowers reduced insect feed-
ing injury on the wild sunflowers and increased their fecundity (Snow et
al., 2003). In another research study, a Bt transgene was transferred from
* Brassica napus to wild B. juncea, and the progeny were backcrossed to
produce a second generation of backcross offspring (Liu et al., 2015).
In research plots, the Bt plants produced more biomass in pure stands
with or without insect pressure than did the susceptible plants. In mixed
stands, however, the susceptible plants produced more seeds when insects
were not present than when insects were present. As the proportion of Bt
plants increased with insect feeding pressure, biomass and seed production
increased, indicating that the presence of the Bt plants may have provided
a level of protection for the susceptible plants. In both cases, it is possible
that gene flow would provide an advantage to wild populations over time.
However, it should be noted that these are research studies with plants that
have not been in commercial use.
FINDING: Although gene flow has occurred, no examples have dem-
onstrated an adverse environmental effect of gene flow from a GE crop
to a wild, related plant species.