How can companies producing GMO plants confirm that their plants will not affect non-GMO plants? Could GMO plants cross with non-GMO plants? If so, has any testing occurred to know what the outcomes are and how they may affect people or other plants?

Expert response from Steve Savage

Consultant, Savage & Associates

Tuesday, 08/13/2013 17:26

Plants can only pollinate members of their own species or sometimes very closely related species.  It is relatively easy to know whether there are any "outcrossing issues" with a new GM plant.  This is one of the issues that the USDA considers whenever it approves of outdoor trials with new GM crops and when it makes the final "deregulation" decision. 

Of course, GM versions of a crop can cross pollinate non-GM versions of the same crop, but this is nothing new to agriculture.  For a very long time, it has been necessary to isolate seed production fields of various crops so that the seed will be of the pure, desired type.  The size of the buffer needed is something well worked out, depending on the crop and how it is pollinated (self-fertilization, wind, insects, birds...).  GM and non-GM seed production can be managed in the same way with regard to this issue.

For most fruit crops, the seed is never used for planting, so cross-pollination is never really an issue, whether the crop is non-GM or GM.  For instance, blocks of different varieties of apples are commonly grown side-by-side (e.g. Fuji next to Gala), and bees may move from one variety to the other. Some of the seeds of those apples might represent a mix of the two varieties, but apples are propagated only by cuttings or bud grafting.  The seed is discarded by the consumer and really shouldn't be eaten because it is cyanogenic.

All of these issues are very familiar to botanists, seed producers and others in agriculture.