Source: CropBiotech Update

New strategies are needed for insect resistance management (IRM) and integrated pest management (IPM) in transgenic crops. These were outlined by Sarah Bates of Cornell University and colleagues, in “Insect resistance management in GM crops: past, present and future,” published in Nature Biotechnology.

Authors recounted several deployment tactics designed to delay resistance, including moderate toxin dosage to ensure the survival of a fraction of susceptible insects; a high toxin dosage to kill insects heterozygous for resistance; the used of stacked genes in transgenic plants; temporal or tissue-specific toxin expression of the genes in question; and “refuge” or provision of non-transgenic plants.

The researchers likewise reported new techniques for integrated pest and insect resistance management. These were the use of pyramided transgenic strains, as in the latest strains of transgenic cotton, which can ensure better pest control, and which require a smaller refuge; and the use of novel toxins, such as Cry and Bt toxins with different modes of action, or vegetative insecticidal proteins (Vips) which have shown insecticidal activity against a wide range of pests.

Researchers also proposed that molecular breeding should be complemented by traditional methods of integrated pest management, including cultural and biological controls.

Full article at www.nature.com/cgi-taf/DynaPage.taf?file=/nbt/journal/v23/n1/full/nbt1056.html&filetype=pdf