The results of genetically modified (GM) wheat trials carried out by Rothamsted Research in the UK confirm that the cultivars grown did not repel aphid pests in a outdoor tillage setting.
This had previously been hypothesised on the back of results achieved from laboratory experiments. Field trails were carried out during the 2012/13 growing season.
The aim of the work was to discover whether wheat could be genetically modified to produce an aphid alarm pheromone and whether it would repel aphids in the lab and field. This would allow farmers to reduce insecticide spraying, benefiting the environment and making farming more sustainable.
Although the GM wheat did not repel aphids in the field, the five-year project did score some notable successes. The use of genetic engineering to provide wheat able to produce the aphid alarm pheromone (E)-β-farnesene (Eβf) was successful and robust – this is a world first and an important proof of concept in plant science overall.
GM wheat plants produced the pheromone in significant quantities without major unexpected changes seen in the appearance or performance of the new wheat plants, which looked and yielded as normal.
In addition, in laboratory experiments aphids were successfully repelled by the Eβf signal. Scientists went on to test the GM plants in open field conditions. However, in the field trials there was no statistically significant difference in aphid infestation between the GM wheat and the conventional wheat used as a control.
Rothamsted’s Professor Huw Jones said he was disappointed in the results of the trial work.
“We had hoped that this technique would offer a way to reduce the use of insecticides in pest control in arable farming. As so often happens, this experiment shows that the real world environment is much more complicated than the laboratory.
“But many aspects of this experiment were highly successful. The genetic engineering component worked very well and GM wheat plants performed as hoped during cultivation. It would have been a fantastic outcome if the experiment had given positive results in the field too but this was not the case and for a first attempt, this was not entirely unexpected.”