March 2003

Corn That Clones Itself

Continued from page 1

By Daniel Charles

The variability problem is even greater with the hybrid varieties seed companies favor. For corn and even for self-pollinating plants, a hybrid's offspring are nothing like the original.

If only corn could reproduce by skipping pollination altogether and cloning itself. The idea is not as far-fetched as one might think. A few plants do this naturally, creating seeds without sex in a process called apomixis. Dandelions reproduce through apomixis; so do about 400 other plant species, including at least one wild relative of corn. So why not corn? If someone could flip a switch and make corn apomictic, CIMMYT might finally be able to make highly productive hardy strains poor farmers could share with their neighbors and replant from their own harvest year after year.

Richard Jefferson, founder of the Center for the Application of Molecular Biology to International Agriculture in Canberra, Australia, says that the implications of apomixis go well beyond corn. The potential of self-cloning plants, he says, is so profound and subversive that plant breeders, generally a cautious and understated lot, "would never admit to dreaming about it unless you got them drunk first."

In addition to bringing hybrid and other superior varieties of corn within reach of even the poorest farmer, apomixis would allow the widespread use of high-yield hybrid rice, plants whose seeds currently are expensive and difficult to produce in large quantities. And apomixis could help eliminate diseases from cassava, an African staple crop that is grown by replanting pieces of tubers from parent plants, some of which carry disease.

After more than a decade of work, researchers at CIMMYT and a handful of other laboratories around the world are finally homing in on apomixis. With the help of new genomic information and tools, they're tweaking the genes that control plant reproduction, hoping to duplicate the self-cloning process in corn and other important crops. If they succeed-and they seem confident that eventually, perhaps in another decade, they will-apomixis will open the door to a "revolution in world food production," says Wayne Hanna, a geneticist with the U.S. Department of Agriculture in Tifton, GA.

That may seem like a technology goal few could argue with. Yet there's uncertainty about whether apomixis ever will be allowed into farmers' fields. Two opposing forces could find themselves unlikely allies in an effort to block it: political opposition to genetic engineering and the financial considerations of agricultural companies that are among the primary sponsors of apomixis research.