Predicting the Environmental Effects of Transgenic Bt Crop Lines
By Alfredo Flores
November 12, 2009
Potential risks from new transgenic Bt crop lines can be assessed using carefully controlled laboratory tests, according to findings of a study by Agricultural Research Service (ARS) scientists and cooperators. This finding will help streamline the assessment process for introducing new insect control technology to the marketplace, while ensuring environmental safety.
Bt (Bacillus thuringiensis) is a biological control bacterium that is effective against a number of key insect crop pests. Crops that contain Bt genes have a built-in defense against these insects, but such crops need to be studied to make sure they don’t pose a risk to non-target organisms.
To test whether the impact of these transgenic crops in the field was predictable from laboratory experiments, scientists from ARS collaborated with researchers at Santa Clara University in California to compare all current laboratory and field studies on non-target effects using meta-analyses. Findings of the ARS study suggest that researchers should be able to more accurately predict from laboratory studies the impact that new experimental lines may have in the field.
Entomologists Jian Duan, Jonathan Lundgren and Steven Naranjo led the study. Duan works at the ARS Beneficial Insects Introduction Research Unit in Newark, Del. Lundgren is based at the ARS North Central Agricultural Research Laboratory in Brookings, S.D. Naranjo is the research leader of the ARS Pest Management and Biological Control Research Unit in Maricopa, Ariz.
The study was initiated to test the underlying assumption of biotechnology risk assessment—that laboratory tests can accurately identify potential risks of transgenic insecticidal Bt crops in the field.. The new ARS study demonstrated that carefully controlled laboratory tests can accurately detect toxicological risks that might emerge in the field, thereby reducing the need for more expensive and time-consuming tests.
The study, completed earlier this year, was published in the journal Biology Letters.
ARS is the primary intramural scientific research agency of the U.S. Department of Agriculture.