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12 December 2013 1:00 pm ,
Vol. 342 ,
Evolutionary biologists have long studied how the Mexican tetra, a drab fish that lives in rivers and creeks but has...
Victorian astronomers spent countless hours laboriously charting the positions of stars in the sky. Such sky mapping,...
In an ambitious project to study 1000 years of sickness and health, researchers are excavating the graveyard of the now...
Stefan Behnisch has won awards for designing science labs and other buildings that are smart, sustainable, and...
The iconic 125-year-old Lick Observatory on Mount Hamilton near San Jose, California, is facing the threat of closure...
Recent results from the Curiosity Mars rover have helped scientists formulate a plan for the next phase of its mission...
A new, remarkably powerful drug that cripples the hepatitis C virus (HCV) came to market last week, but it sells for $...
In pretoothbrush populations, gumlines would often be marred by a thick, visible crust of calcium phosphate, food...
- 12 December 2013 1:00 pm , Vol. 342 , #6164
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Resistant Weed Could Outdo Crop
6 August 1998 8:00 pm
BALTIMORE--Weeds that acquire genes for herbicide resistance from a genetically engineered crop can reproduce just as well as nonhybrid weeds. The finding, reported here today at the Ecological Society of America's annual meeting, suggests that scientists will have to find more sophisticated ways to engineer plants to prevent valuable traits from escaping into nearby weeds.
Spraying entire fields with herbicides is much more efficient than targeting just the weeds. To take this broad-brush approach, scientists insert herbicide-resistance genes into the DNA of crops. But when the crop plants release pollen, weedy relatives growing near the crops can take up the resistance genes through the pollen. Because cultivated crop plants are generally less robust than weeds, however, researchers have thought that any genetic mixing should result in less hardy weeds.
To test this idea, plant biologist Allison Snow of Ohio State University in Columbia and colleagues at the Risoe National Laboratory in Roskilde, Denmark, crossed a herbicide-resistant version of Brassica napus, the rapeseed plant used to make canola cooking oil, with its weedy cousin, Brassica rapa. They grew the hybrid weeds and compared them to regular weeds. Both produced similar amounts of seeds and thus could reproduce equally well. This means that crops won't have any edge in competing with weeds, says Snow.
But some experts are not convinced that resistant weeds will be a widespread problem. "There's not many crops that have weedy relatives in the U.S." that could accept the resistance genes, says Juliette Winterer, a population biologist at Franklin & Marshall College in Lancaster, Pennsylvania, although resistance may spread from carrots, squash, and sunflowers as well as rapeseed. Scientists may try to circumvent this gene transfer by inserting genes into a crop plant cell's cytoplasm, where they can only be inherited through the seeds.