100-Year-Old Wheat Could Help Feed the World

In the 1920s and ‘30s, a British botanist named Arthur Ernest Watkins collected over 1,000 varieties of bread wheat from 32 countries all around the globe.

In a recent study, scientists propose that his seed collection – which has been painstakingly maintained for over a century – could hold the key to fortifying modern wheat agriculture and feeding the world’s ever-increasing population. Their findings were published in the journal Nature in June 2024.

Upon Watkin’s return from France after World War I where he worked as an assistant agricultural officer, he and his colleagues had predicted that scientific advancements in plant breeding would greatly decrease crop diversity. He was thus tasked with safeguarding landraces – local wheat varieties – from across the globe. To date, the wheat assortment he assembled is the most comprehensive collection of historic wheat in the world.

Today, what Watkins predicted a century ago has largely taken place. The “Green Revolution” of the twentieth century brought about a dramatic increase in grain production thanks to the development of high-yielding varieties, especially wheat and rice. But yield wasn’t the only trait that changed as a result of modern breeding techniques.

“In the past 100 years, the wheat yield has increased, but our modern wheat cultivars are quite fragile with a dramatic reduction and homogenization of genetic diversity,” says Shifeng Cheng, a lead author of the study and Director of the Plant Genomics Center at the Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences.

“We lost the protein, the nutrition content, lots of good traits. And that’s a big problem to ensure food security in the face of changing global climates,” adds Cheng.

Modern wheats mostly originated from central and western Europe and descend from only two ancestral groups – which is very few given that the Watkins collection alone represents seven ancestral groups. The problem with a lack of diversity is that it makes crops more vulnerable to just about everything.

“If there is some unpredictable pest, disease, or climate change phenomenon, many of our wheats will be wiped out in the growing years,” Cheng explains. “We needed to go back to the history, go back to the lost diversity.”

To do this, the international team of Chinese and British scientists turned to the Watkins collection to rediscover historic wheat diversity. “Diversity creates complexity for robustness and innovation,” Cheng adds.

Maintaining the wheat collection was truly a gargantuan effort: the seeds needed to be planted, grown, and recollected at least every 5 years. Of the 1000 landrace varieties that Watkins had collected from European, Asian, and North African countries, 827 survived to see the study that started 12 years ago.

The scientists painstakingly analyzed the wheat, whose genome is infamously five times bigger than the human genome and discovered that the Watkins wheat collection represents 67 percent more genetic diversity than modern varieties.

“The Watkins wheat was collected 100 years ago, but each variety of wheat was grown and fed people for hundreds or even for thousands of years,” Cheng explains. “They adapted well to local environments, could withstand environmental hardships, and maintained a rich, underutilized source of diversity.”

The team characterized and projected 137 traits from the landraces into a genomic variation map – what Cheng calls a “gene dictionary” that can help wheat communities breed ancient useful genetic diversity back into modern wheat varieties. Some of the lost traits identified by the scientists include higher nitrogen use efficiency, slug resistance, and resilience to pests and diseases.

“If we have a lot of diversity, when a new disease comes in, maybe there’s a variety that is fortunately resistant to that disease. That’s the ecosystem we need,” Cheng says. “We need the diversity so we can deal with unpredictable events.”

Genetic diversity can make wheat hardier and gives the world’s wheat production a higher chance of rebounding from disease, pests, bacteria, and climate change events.

The scientists have already crossed 119 varieties from the Watkins collection with modern wheat to make a new collection of 12,000 varieties, which are currently stored in the Germplasm Resource Unit at the John Innes Centre and were introduced into China for more experiments. However, Cheng says there’s still a gap to fill between these results and modern breeders.

“We tested the genetic and phenotypic effects,” Cheng explains, “But the farmer doesn’t necessarily care. They might ask, ‘how can your work help me?’ To make a real-world impact, we need to build the connection between scientists and farmers, between fundamental research and applied breeding, to deliver our results to the farmer.”

In view of this mission, the team created a free Academic and Breeding’ Toolkit to help breeders put their findings into practice, but Cheng thinks there is still a long way to go. Because their study involves a lot of data that needs to be processed, he’s hopeful that artificial intelligence can support future efforts.

Ultimately, the Watkins collection provides a beacon of hope for the development and adoption of hardier wheat to more sustainably feed the world’s growing population.

Tags: yield, food security, varieties, grain, rice, Bread, Production, wheat