Ancient Wheat Compound Offers Natural Protection Against Aphids

Scientists at Rothamsted Research have uncovered a natural defence mechanism in ancestral einkorn wheat that could pave the way for more sustainable pest control in modern agriculture.

The study, published in the Journal of Agricultural and Food Chemistry, reveals the discovery of saponarin—a flavonoid naturally present in Triticum monococcum—which significantly reduces the survival of the English grain aphid (Sitobion avenae), a major pest threatening wheat crops worldwide.

Aphids damage wheat both by feeding and by transmitting viruses such as barley yellow dwarf virus (BYDV), which can cause yield losses of up to 80%. Current control strategies rely heavily on insecticides—a practice increasingly challenged by resistance, regulation, and environmental concerns. This discovery opens the door to breeding wheat varieties with natural aphid resistance, reducing pesticide dependence and supporting sustainable agriculture.

The research focused on two lines of T. monococcum (MDR045 and MDR049), previously shown to contain resistance against S. avenae and the Bird cherry-oat aphid (Rhopalosiphum padi). Leaf extracts from these lines significantly reduced aphid survival in feeding assays. Using bioassay-guided fractionation, the team identified saponarin as the key compound behind this resistance. Its activity was unique compared to other plant flavonoids tested, except for naringenin.

“These findings highlight the untapped potential of ancestral crop species in modern agriculture,” said Dr. Alexander Borg, co-author of the study. “By identifying and understanding natural resistance traits, we can integrate them into elite wheat varieties and reduce reliance on synthetic pesticides. Discovering saponarin as a key bioactive compound marks a step toward sustainable pest management and opens new opportunities for integrated crop protection.”

This research underscores the value of ancient grains as a source of natural defence mechanisms—tools that modern agriculture may soon harness to create more resilient, climate-smart crops.