Wheat plants cross-bred with exotic DNA from wild relatives deliver up to 50% higher yields in hot weather compared with elite varieties lacking these genes, new research has shown.

Following a year in which temperature records have been smashed, the findings offer hope for improving crop resilience and food security in the face of climate change, say scientists.

See also: Food security must top the bill in 2023, say farm leaders

Wheat is grown worldwide and is responsible for about 20% of calories consumed globally.

British researchers from the Earlham Institute in Norwich set up a two-year field trial in Mexico’s Sonora desert in collaboration with the International Maize and Wheat Improvement Centre (CIMMYT).

They studied 149 wheat lines, ranging from widely used elite lines to those selectively bred to include DNA from wild relatives and landraces from Mexico and India. 

The researchers sequenced the plants to locate specific genetic differences responsible for the increased heat tolerance.

Later sowing

The seeds were sown later in the season to force the plants to grow during hotter months, putting these crops under the kind of heat stress that is predicted to become the norm as global temperatures rise.

They found the plants bred with exotic DNA achieved a 50% higher yield over wheat without this DNA. Importantly, the exotic lines didn’t perform any worse than the elite lines under normal conditions.

The paper, Exotic alleles contribute to heat tolerance in wheat under field conditions (PDF), has been published in the journal Communications Biology.