Contents - Faperta

506 Biotechnological Approaches for Pest Management and Ecological Sustainability
•
Genetic linkage maps of economically important insects; and
• Quantitative trait loci (QTLs) associated with insect behavior and insect-plant
interactions.
Development of New Insecticide Molecules and Monitoring Insect
Resistance to Insecticides
Crop protection is still dominated by chemical control, and this approach will continue to
be important in crop protection. Traditionally, the discovery of new agrochemicals has used
in vivo screens to identify new compounds. Functional genomics offers the opportunity to
acquire in-depth knowledge of the genetic makeup and gene function of insect pests that
may lead to the discovery of new processes that could be the targets for novel chemistry
(Hess, Anderson, and Reagan, 2001). Combining genomics with high-throughput biochemical
screening can be used for a range of new chemicals for pest control. Genomic
technologies are now allowing investigation of some previously intractable mechanisms
involved in insect resistance to insecticides. New molecular techniques permit fundamental
insights into the nature of mutations and genetic processes such as gene amplifi cation,
altered gene transcription, and amino acid substitution to underpin insecticide resistance
mechanisms. This, in turn, will lead to high-resolution diagnostics for resistance alleles in
homozygous and heterozygous forms, especially for insect pests with multiple resistance
mechanisms, or for resistance mechanisms not amenable to biochemical assays. Future
efforts in this area should focus on:
• Functional genomics that may lead to development of molecules with different
modes of action;
• Genetic linkage maps of insects, and QTLs associated with different resistance
mechanisms; and
• Diagnostic kits for detecting resistance to a group of insecticides with the same
mechanism of resistance or with different resistance mechanisms.
Marker-Assisted Selection and the Genomics Revolution
The last decade has seen the whole genome sequencing of a number of model organisms
(Chalfi e, 1998). Systematic whole genome sequencing will provide critical information on
gene and genome organization and function, which will revolutionize our understanding
of crop production and provide an ability to manipulate traits contributing to high productivity
(Pereira, 2000). Advances in plant genomics will fuel the mapping of QTLs associated
with resistance to insect pests. Use of QTLs will also facilitate rapid and effi cient
transfer of genes conferring resistance to insects from wild relatives of crops. Some of the
secondary plant metabolites, such as fl avonoids, terpenoids, and alkaloids, have been
implicated in host plant resistance to insects, and some of these metabolites accumulate in
plants in response to biotic and abiotic stresses. Biotechnology also offers the promise
to increase the production of secondary metabolites in plants that are used in medicine,