Emerging Technologies for Crop Breeding
The production and evaluation of genetically
modified (GM) crops is an active area of re-
search, but the access of growers to this tech-
nology in many countries is currently restricted
primarily because of political and bioethical
issues (Box 1). Nevertheless, GM technologies
permit the generation of novel variation beyond
that which is available in naturally occurring
(or even deliberately mutated) populations.
Classic applications of GM include the use of
proteinaceous toxins to control insect pests and
“golden rice,” which is biofortified with vita-
min A (11). Crucial to the future deployment of
GM crops are the discovery and characteriza-
tion not only of genes but of promoters that
provide accurate and stable spatial and tempo-
ral control of the expression of the genes (12).
Development of cis-genic vectors and marker-
free transgenic plants (Box 1) may help to ease
some of the political concerns about GM tech-
nologies. Nevertheless, the widespread appli-
cation of GM technologies will remain limited
while regulatory demands impose high costs
on releasing GM crops (Box 1). Although it is
likely that most of the important contributions
to crop improvement in the coming 5 to 10 years
will continue to be from non-GM approaches, we
consider that transgenic technologies will inevi-
tably be deployed for most major crops in the
future.