Given the political impediments to GM, conventional
breeding is being focussed on by all but the largest seed
companies because small companies cannot afford the
costs of developing GM crops. Even large multinational
companies such as BASF and Monsanto have decided to
focus on conventional breeding for the European market
although biotech crop development continues in other
parts of the world. With marker assisted selection (MAS)
the speed of conventional breeding can be improved [33]
but it still remains a challenge to introgress beneficial
traits from distant germplasm. The distinction between
conventional and GM is increasingly unclear as conventional
breeding allows random mutagenesis [31] while
GM techniques, such as site directed mutagenesis, are
becoming increasingly precise [34], not only for switching
off genes but also for switching them on [35
]. Whatever
the method of crop genetic improvement, there is considerable
potential to increase protection of crops from
insect attack by planting insect resistant seeds. We are
currently doing GWAS in collaboration with ICRISAT
and Cornell University in order to provide molecular
markers for MAS of indirect defence traits in maize.
Conclusions
There is considerable potential to improve crop defences
against insect attack by learning from nature and introgressing
traits from crop wild relatives or landraces. For
our maize example, the discovery of two hybrid varieties
and three inbred parental lines that possess the indirect
defence trait elicited by insect eggs in hybrid maize is
promising. This demonstrates a real prospect of introgressing
the trait into higher yielding hybrid maize varieties in