Prepare to hear more about gene flow. The term refers to spontaneous movement of genes from one species to a related species. Or maybe even to an unrelated species.
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| A U.S. geneticist examines a soybean plant's integrated genetic linkage map in this file photo. -- Photo by Keith Weller, courtesy USDA/ARS. |
If that sounds like a topic just for academic discussion, consider the implications of a key gene moving from drought-resistant genetically modified (GM) wheat to a related grassy weed. A parallel issue is who carries legal responsibility for financial losses resulting from such events: the corporate supplier of the trait? Farmers who grow the GM crop?
Facing questions such as those, and with numerous new crop traits in the pipeline, gene flow takes on added significance. The issue is greatest in cross-pollinated crops that produce abundant light pollen distributed by wind. But bees and other insects can also carry pollen great distances. And pollen can even sometimes be transferred from self-pollinated plants like soybeans.
How do you stop gene flow from GM crops? The question was examined by a panel of experts at Bayer's weed resistance conference, which concluded in Miami Jan. 21. They decided it will be a tough challenge, partly because knowledge is limited. Exactly how and to what extent genes transfer from one species to another, or even within the same species, is not fully understood.
The science of gene identification and analysis is progressing rapidly, however, and the knowledge gaps are expected to fill sooner rather than later. Even so, panel members did not predict a one-size-fits-all answer.
Rather, they saw the need for detailed and intense case-by-case analysis before new crop traits come up for registration. In some situations, they suggested the terminator (sterility) genes, abandoned a decade ago because of adverse public opinion, might be worth a second look.
In other situations, they reluctantly admitted, the crop protection industry might have to decide that genes with great economic potential are just too risky to release. Still other traits could be so potentially valuable as to be worth some degree of gene-flow risk.
This level of caution suggests farmers should not hold their collective breath when revolutionary new crop traits are announced. The road they take from discovery to commercialization could be long, difficult and controversial.