This archive report was first published on 8 July 2020.
On July 8, 2020, a breakthrough study published in Scientific Reports revealed that 'smart' maize varieties have the ability to defend themselves against stemborers by releasing odours that attract natural enemies of the pest.
The research, conducted by the International Centre of Insect Physiology and Ecology (ICIPE), Keele University, and International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), analysed the genetic makeup of 146 different types of maize plants.
According to Dr Amanuel Tamiru, Scientist at ICIPE, the defence reaction is triggered in the plants when stemborers lay eggs, releasing odours that attract wasps capable of parasitizing the pests.
Dr Tamiru explained, “An interesting finding is that the plants recruit both egg and larval parasitic wasps. As such, the natural enemies parasitize and kill the stemborer eggs before they hatch into larvae, as well as any larvae that may emerge, thus pre-empting damage on the crop.”
The scientists found the defence trait to be more common in landraces than in improved inbred lines and hybrids.
Prof. Toby Bruce, Keele University, noted, “The fact that we were able to pinpoint the regions in the maize genomes associated with this safeguarding response is important. It means that our findings could be used by maize breeders to promote stemborer resistance in maize cultivars preferred by farmers because of other desirable traits.”
