Traditional seed supply found to have GM DNA

If you read nothing else read this – April

What is new about the Gone to Seed report?

Gone to Seed reports, for the first time, that the traditional seed supply for important food crops is contaminated with DNA from genetically engineered crops. UCS tested six traditional varieties each from three crops—corn, soybeans, and canola—and found that most of them carry pieces of DNA from genetically engineered varieties.

Why is contamination of the traditional seed supply important?


Bt crop: Insect-resistant crop variety engineered to produce an insect toxin originally found in a soil bacterium. YieldGard, NaturGard, KnockOut, and StarLink are trade names of some Bt-corn varieties.

DNA: Deoxyribonucleic acid, the linear macromolecule that makes up the genetic material of most organisms. DNA usually exists as a double-stranded helix.

Gene: Functional unit of hereditary material usually carried on chromosomes and passed from parent to offspring. A gene codes for proteins (the molecules that are responsible, alone or in combination, for traits exhibited by plants such as seed color and shape, height, and insect resistance).

Genetic engineering: Molecular-level techniques capable of combining genes and regulatory sequences and transferring them into an organism. These techniques, which may be used to transfer genes between unrelated organisms or to remove and rearrange genes within a species, are also called  transgenic, gene splicing, and genetic modification techniques.

Herbicide-resistant variety: Plant variety resistant to the otherwise toxic effects of herbicides.

Pollen: Dust-like material, produced by the male parts of flowers, which contains male sex cells.

Primer set: Short pieces of DNA added to polymerase chain reaction (PCR) mixtures to “find” the pieces of target DNA that will be copied. Primer sets are synthesized to match sequences at the beginning and end of the target DNA, thereby defining the exact segment to be subsequently duplicated by a DNA-copying enzyme.

Traditional seeds represent the portion of the seed supply that is presumed not to be genetically engineered. Such seeds are important to conventional farmers exporting crops to countries that reject  genetic engineering; to organic farmers who are barred from using genetically engineered seeds; and to society as a whole as an insurance policy against the possibility that something might go awry with genetic engineering.

How did the contamination occur?

UCS is not sure. We do know that there are two major routes by which the DNA we detected could move into seed supplies: physical mixing  of seeds or seed parts, and pollen, which is carried by wind or insects to the female parts of plants and gives rise to new seeds. But we do not know whether seed mixing or pollen flow or both account for the engineered genetic material we found in traditional varieties in our study.

What kinds of genetically engineered elements are contaminating traditional varieties of seeds?

Again, we do not know. We could only test for a few genes—those that are used in popular herbicide- resistant and Bt varieties of genetically engineered crops—and we did detect some of those genes. But there are many other genes that could potentially contaminate traditional seeds that we could not test for. Gone to Seed lists hundreds of genes and traits that have been moved into varieties of soybeans, corn, and canola, such as genes added to corn to produce drugs for people and animals and to alter the crop’s starch, oil, and protein makeup.

If corn, soybeans, and canola are safe to eat, why would anyone be concerned about the low levels of seed contamination that UCS found?

Well, first, we’re not sure what the levels of contamination across
the seed supply really are, although the limited data in our study suggest that it is low. One reason we advocate a large follow-up study is to obtain better estimates of the levels of contamination.

Second, the answer depends on what kinds of traits the contaminating DNA sequences produce. Some substances are active at very low concentrations. Corn on the cob laced with low levels of a human growth hormone drug would be a problem, for example, while a protein already present in food plants might not be.

In the environmental realm, it is important to remember that low levels of genes in crops do not mean low levels in the environment. Genes that escape from agricultural fields into the environment can be reproduced and increase in prevalence under congenial circumstances.

Finally, low levels of contaminants may affect international trade and our food system. For example, if engineered genes are not approved by an importing government, whole shipments of U.S. grain might be rejected. Or, the detection of unapproved genes for pesticides like Bt in food might subject food processors to liability and disrupt the food system. Even though no one is injured, such incidents as the StarLink episode of a few years ago can end up costing a good deal of money.

Hasn’t the U.S. government determined that engineered varieties of corn, soybeans, and canola are safe for human consumption and the environment?

To begin, an important background point. Most biotechnology foods in the United States are not formally approved for human consumption. Products pass through a voluntary system at the end of which the Food and Drug Administration states that it has no furthers concerns. In addition, the U.S. government oversight of environmental risks is weak and almost none of the existing biotechnology regulations specifically address the need to protect the seed supply.

That said, the contamination of seeds with genes from those few kinds of biotechnology crops that are now allowed on the U.S. market is not alarming.

What does concern us, however, are the many other genes that might have made their way into the seed supply during the process of field testing. There are hundreds of such genes, including those from pharmaceutical and industrial crops, never intended for human consumption. It was not possible for UCS to test for these genes, but in theory any one of them could have contaminated seeds for traditional varieties. Of even greater concern is that the identities of many of the field-tested genes are not available to the public because they have been declared confidential business information.

What are pharmaceutical and industrial crops? Did UCS discover genetic material from these crops in the traditional seed supply?

Many in the biotechnology industry predict that the next wave of new products will be crops—often food crops—engineered to produce drugs and industrial products like plastics. These so-called pharm and industrial crops have been field tested in the open in the United States for over a decade and in theory could have contaminated our seed supplies.

We were not able to test for the presence of pharm or industrial crops because the primers needed to do such tests are not publicly available, but if seeds are vulnerable to contamination with the genes we detected, they are vulnerable to contamination with pharm and industrial crop genes as well.

Does the U.S. government know which engineered sequences are moving into our traditional seed supply?

No. The U.S. government has not focused on the possibility that seeds of traditional crop varieties are contaminated with genetically engineered DNA. There is no program underway to systematically test traditional seeds for the presence of genetically engineered sequences.

Will the seed contamination problem worsen over time?

In general, the answer is yes. Left unchecked, we are likely to have more and more genes at higher and higher levels in our traditional seed supply. But we do need to understand more about when and where contamination occurs. That is why we urge the federal government to promptly follow this pilot project with a much more comprehensive study with large samples of a greater number of crops.

Can I avoid engineered contaminants by buying organic food?

Yes, for the most part. Organic standards forbid the use of genetically engineered seeds and inputs in agriculture. The organic industry is doing everything it can to avoid contamination with genetically engineered DNA and to a large extent it is succeeding.

But organic farmers cannot avoid pollen coming into their fields and cannot readily detect genetically engineered seed mixed into the seed they purchase, so sometimes, through no fault of their own, organic producers are not able to deliver the pure product that their customers want.

Even if engineered DNA is occasionally found in organic food, consumers should not lose faith in organic agriculture. No sector of the food system is trying harder to meet consumer demand for choice.

Can’t the government just set tolerances for engineered contaminants—say, that any contaminant below one or two percent won’t matter for legal purposes?

Tolerances for acceptable levels of contaminating DNA sequences might make sense in certain circumstances. But for the government to set tolerances, it needs to know what kinds of genes are present in grain or food. Our report suggests that the government does not know what kinds of engineered genes are making their way into the traditional seed supply and therefore does not have a scientific base on which to set tolerances.

What is UCS recommending be done to address this pervasive contamination of the seed supply?

UCS has eight recommendations in the report. The three most important are:

  • a follow-up study to determine the extent and causes of the problem;
  • prompt revision of the pharm and industrial crop regulations to protect the seed supply; and
  • a commitment to a reservoir of pure non-engineered seeds.

Why is it important to maintain reserves of “pure” seeds?

We need a reservoir of pure seeds as an insurance policy in case something goes awry with genetic engineering. Genetic engineering is a radically new and complicated mode of adding new traits to crops. While much of our experience with the technology to date is positive, it is simply too early to declare the technology to be completely safe. The prudent course is to maintain a portion of the seed supply that is free of genetically engineered sequences for some period of time.

What can consumers concerned about the purity of the seed supply do to prevent further contamination?

Just being aware of the problem is a start.

UCS recommends that consumers:

Original article from Union Of Concerned Scientists


One response to “Traditional seed supply found to have GM DNA

  1. Why is it important to maintain reserves of “pure” seeds? this site is good for farmers.

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