Frequently Asked Questions

Please select a question from the list below to jump to the answer.

• What crops derived through biotechnology does DuPont currently market?
• Can cross-pollination occur between crops derived through biotechnology and wild, native plants?
• If pollen from a crop derived through biotechnology is carried to a wild relative, are the genes automatically transferred to the wild relative?
• What is the likelihood the new genes in crops derived through biotechnology will be transferred to wild plants?
• If gene flow occurs, are negative ecological impacts inevitable?
• Can herbicide tolerant genes move from crops derived through biotechnology into weeds and create "superweeds?"
• Will gene flow from crops derived through biotechnology decrease the genetic diversity of wild plant species?
• Do regulatory agencies assess the potential for gene flow and its consequences during their review of crops derived through biotechnology?

DuPont currently markets three crop varieties developed using biotechnology: soybean and canola that are tolerant to the herbicide glyphosate; and corn that provides protection against specific insect larvae that feed on corn and against the herbicides glufosinate and glyphosate. These products, sold under the Pioneer® brand, provide farmers with new crop management options and increased productivity. Before marketed, these products were rigorously tested and reviewed by regulatory authorities for food and feed safety, environmental impacts and product performance.

Cross-pollination can occur if the crop and wild plant are very closely related, whether the crop is derived through conventional breeding or biotechnology. However, many factors limit cross-pollination between crops and their wild relatives, such as the proximity of the crop and wild relative; compatibility of their reproductive cycles; tendency to self-fertilize; and the length of time pollen is viable.

No. A number of factors determine whether pollen transfer leads to gene transfer, the most important being the degree of relatedness between the crop and wild relative. Gene transfer depends upon crop pollen fertilizing the egg of the wild plant. Cross-fertilization must lead to the production of hybrid seeds that are fertile and produce offspring for gene flow to occur. These are key examples of the barriers that nature provides to minimize the potential for interbreeding between different plants.

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The answer to this question varies with the crop, the location where it is grown and the wild plant. The one general statement that is true for all crops is that genes can potentially be transferred only in those locations where the crop has wild relatives. Therefore, to assess the likelihood of gene flow from any crop to its wild relative, first determine whether the crop is growing in a geographic region that contains wild relatives. If not, the likelihood of gene transfer is zero. If wild relatives are growing in close proximity to the crop, then a number of factors influence the likelihood of gene flow, such as the distance viable crop pollen can travel, the amount of crop pollen produced, the mode of pollination, and the number of wild plants in proximity to the crop.

Looking at the experience gained from growing conventionally bred crops for many decades, it seems that very rarely, if ever, will gene flow from a crop to a wild relative have a significant ecological impact. Gene flow from a conventional crop to a wild, weedy relative has been documented. In a few instances, the new genes have had a negative impact on crop management because controlling the hybrid weed growing in fields of the conventional, related crop became more difficult. However, adverse effects on agricultural systems should be distinguished from negative impacts on natural ecosystems. Past gene flow from conventional crops to wild, native plants appears not to have had a noticeable impact on natural ecosystems. In order to have negative environmental effects, the gene must become widespread in the wild plant population and give the wild plants possessing the crop genes a competitive advantage over those without the crop genes.

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Herbicide tolerant genes can move from some crops to certain weedy relatives in some locations, but this will not necessarily lead to the creation of superweeds. Weedy relatives might acquire tolerance to a specific herbicide, but if the weedy relative is not treated with that herbicide, then having the new gene offers no competitive advantage. Even though the weed may no longer be susceptible to that herbicide, it can be controlled with a number of other herbicides.

Because fertilization of wild plants with crop pollen is relatively rare when compared to fertilization of a wild plant with wild plant pollen, gene flow from crops to wild plants will rarely, if ever, have a significant impact on the genetic diversity of wild plants.

Yes. In the U.S., assessing the likelihood and impacts of gene flow is a component of the regulatory review process at both the U.S. Department of Agriculture (USDA) and the Environmental Protection Agency (EPA). Regulatory bodies in other countries also require the submission of data on gene flow probability and its potential impacts.

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