Biotech companies should steer clear of producing transgenic crops with beneficial traits that may be passed on to weeds, said a recent Ohio State study using radishes.

Transgenic crops contain a gene or genes that have been artificially inserted when the plant would have naturally acquired them through pollination. Plants are engineered with specialized traits such as resistance to insects, viral diseases and herbicides.

“What I did in my study was not transgenic because the radishes fertilized naturally. However, biotech companies are doing the same thing, only artificially,” said Allison Snow, study co-author and professor of ecology. “Whenever you put a new gene into crop plants, the gene will be affected.”

A genetic trait passed from crops to their weedy relatives can last up to six generations, and possibly longer, the study said. A weedy relative is anything closely related to a crop, said Jeff Stachler, a weed science extension assistant in the Horticulture and Crop Department.

“All crops were weeds at one time until someone realized that the plant might have a benefit as food,” Stachler said. “The crop has progressed over time.”

Transgenic fertilization poses the problem of the genetic trait developed in the crop becoming a permanent part of the weed population and that can be a possible risk to crops, the study said.

“It’s inevitable that these and other fitness related traits will make their way into the weed populations,” Snow said. “The result will be very hardy, hard-to-kill weeds.”

Researchers included Snow, OSU graduate student Kristen Uthus and Theresa Culley, a researcher at the University of California, Irvine. They studied four populations of hybrid and wild radishes for six years in Michigan.

The researchers looked for four genetic traits: Two enzymes, flower color and pollen fertility.

On average, wild radishes reached peak flowering one month before the hybrid plants and that the hybrid plants produced fewer seeds per fruit than the wild plants, the study said. But traits from the original crops, such as white flower color, appeared in subsequent generations of hybrid radishes.

“Even though the effects of delayed flowering and reduced fertility inhibited the movement of certain crop traits to later generations, we did find evidence of crop genes in every generation,” Snow said.

Researchers also found that the hybrids were capable of ecologically significant levels of reproduction. The new hybrid weeds may not be as fit as their wild parents, but they seem to gain reproductive fitness quickly, Snow said.

Many farmers choose to use herbicides on their crops to control pests and disease, but the government strictly regulates the quality of products on our grocer’s shelves.

“As for a stronger herbicide being produced because of crop resistance, that is unlikely because of strict government mandates,” Stachler said.

Snow, who is now researching gene transfer in sunflowers, feels it is important for biochemical companies to consider the consequences of engineering specialized traits in crops.

“When you have genetically modified crops, there is no way to keep their genes from escaping,” Snow said.