A TYPE of maize that won鈥檛 breed with other strains could help organic
farmers keep their fields free from contamination with genetically modified
crops. The technology could also help prevent food crops from mingling with
plants not intended for human consumption.
Until now, organic farmers have had to rely on buffer zones to prevent pollen
from modified crops fertilising their plants. But Jerry Kermicle and his
colleagues at the University of Wisconsin, Madison, discovered that teosinte, a
wild cousin of maize, has a natural talent for blocking foreign genes. Through
conventional breeding, Kermicle鈥檚 team has developed corn that resists
pollination from GM varieties.
About 15 years ago, Kermicle noticed that teosinte weeds in cornfields were
especially good at blocking pollen from neighbouring maize. 鈥淲e know nothing
about the mechanism other than that it involves an interaction between pollen
grain and the silks of the ear parent,鈥� Kermicle says.
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With the help of Steve Gerrish, a plant breeder at the Wisconsin Alumni
Research Foundation, Kermicle bred this trait into several varieties of feed
corn. This corn resists pollination from at least two different kinds of GM
corn, and Gerrish now wants to introduce the trait into sweetcorn. 鈥淏y the fall
of 2003, the planting season, companies could have commercial quantities.鈥�
Gerrish expects maize growers to be especially interested after the recent
taco shell fiasco
(快猫短视频, 7 October, p 6).
鈥淲e can plant side by side, and your corn will not pollinate mine,鈥� he says.
Stuart Reeve of the National Corn Growers Association in St Louis, Missouri,
says the technique is interesting. 鈥淚t would obviously be a tool that would get
a lot of plant breeders looking at it.鈥�
Some organic farmers have had their crops rejected because they were tainted
by GM crops, says Holly Givens of the Organic Trade Association in Greenfield,
Massachusetts. But while this type of corn could solve the problem, she thinks
the real solution is a ban on all GM crops.
Sue Mayer of GeneWatch, a British environmental group, agrees. She also
questions the rationale for barrier technologies. 鈥淚t鈥檚 extraordinary the ends
people are expected to go to to accommodate GM,鈥� she says.
Val Giddings of the Biotechnology Industry Association in Washington DC also
questions the need for barrier technology鈥攂ut for quite different reasons.
鈥淔ears that have no basis in biology are certainly worth addressing but it
doesn鈥檛 make sense to address them with a biological solution.鈥�