The Political Economy of Regulation of Biotechnology in Agriculture - The Oxford Topic of Food, Politics, and Society - page 703

to biodiversity, soil health, and water quality would be just as acute in these cropping
systems as those that include GM crops. Neither of these systems is well buffered from
unanticipated shocks, such as drought, disease, or pestilence. Thus vulnerability is high,
as seen with corn crops in the US Midwest that experienced severe drought in 2010-
2012. The threat to biodiversity posed by GM crops is far more nuanced. The US regu-
latory system examines each successful transgenic “event”54 in terms of biosafety. The
approved “event” is then hybridized with a wide variety of genotypes that have already
been selected for their performance in the range of conditions in which the seeds will be
sown, and this germplasm represents hundreds of varieties. In non-GM conventional
agriculture catering to MNCs, the genetic diversity is, by comparison, significantly
reduced. The aim is uniformity, which is achieved largely by limiting genetic diversity.
In this light, the argument that rejection of GM crops by some multinationals protects
biodiversity is simply not valid.
Blocking/Managing Gene Flow and Adventitious Presence
There are two major approaches to managing gene flow: use of spatial and/or tem-
poral separation and genetic engineering. The first approach involves preventing
cross-pollination by use of spatial or temporal isolation in the field. Spatial isolation is
achieved through the use of specific isolation distances and use of buffer zones where
trap crops are planted to act as a pollen barrier. Temporal isolation takes advantage
of differences in flowering time between different crop cultivars (Devos et al. 2009).
Both approaches require that neighbors meet and agree on how to contain the GM
crop to enable non-GM producers to also thrive. Other important means to prevent
adventitious presence is to thoroughly clean all equipment that might have been used
for processing GM seeds, including planting and harvesting equipment, vehicles
used to transport seeds, seed storage facilities, and any location where commingling
could occur in processing plants that produce both GM and non-GM products.
The second and more controversial approaches to restricting gene flow employ
genetic engineering to biologically “contain” the transgenes by (1) reducing or
eliminating pollen shed; (2) eliminating transgene presence and/or expression in
pollen by transforming organelles (i.e., plastids in plants) whose DNA is not con-
tained in pollen, thus preventing the transfer of transgenes during pollination
(transplastomic plants); (3) use of sterile male lines (cytoplasmic male sterility)
and (4) cross-incompatibility. Publicly funded research organizations in the United
States have undertaken work using these classic approaches, along with genetic engi-
neering approaches to “biocontainment” to reduce the potential for gene flow from
GM to non-GM crops. The latter are referred to as genetic use restriction technolo-
gies (GURT), the most notorious of which has been dubbed the “terminator” tech-
nology by anti-GM activists. While a working model was developed jointly by Delta
Pine Land and the USDA and purchased subsequently by Monsanto Corporation,
the technology was never proven in field trials or commercialized. Despite this,