In the 1920s and 1930s, a British botanist named Arthur Ernest Watkins collected over 1,000 varieties of bread wheat from 32 countries around the world.
In a recent study, scientists suggest that its seed collection – carefully maintained for over a century – could hold the key to strengthening modern wheat farming and feeding the world’s ever-growing population. Their findings were published in the journal Nature in June 2024.
The Green Revolution
When Watkin returned from France after World War I, where he had worked as an assistant agricultural officer, he and his colleagues had predicted that scientific advances in plant breeding would greatly reduce crop diversity. He was therefore entrusted with the task of protecting landraces – local varieties of wheat – from around the world. To this day, the range of wheat he assembled remains the most comprehensive collection of historic wheat in the world.
What Watkins predicted a century ago has largely come to pass today. The “Green Revolution” of the 20th century brought a dramatic increase in grain production thanks to the development of high-yielding varieties, especially wheat and rice. But yield was not the only trait that changed as a result of modern breeding techniques.
“Over the last 100 years, wheat yields have increased, but our modern wheat varieties are quite fragile as genetic diversity is dramatically decreasing and becoming standardized,” says Shifeng Chengone of the lead authors of the study and director of the Plant Genomics Center at the Agricultural Genomics Institute in Shenzhen, Chinese Academy of Agricultural Sciences.
“We have lost the protein, the nutritional content and many good properties. And this is a big problem for ensuring food security in the face of the changing global climate,” Cheng adds.
Read more: Alternative “meat” could be our biggest climate solution
The importance of wheat diversity in modern agriculture
Today’s wheat species originate mostly from Central and Western Europe and are descended from only two ancestral groups – which is very little considering that the Watkins collection alone Seven ancestral groups. The problem with a lack of diversity is that it makes crops more vulnerable to pretty much everything.
“When unpredictable pests, diseases or climate changes occur, many of our wheat varieties are wiped out in the growing years,” explains Cheng. “We had to go back to history, back to the lost diversity.”
To this end, the international team of Chinese and British scientists turned to the Watkins collection to rediscover historical wheat diversity. “Diversity creates complexity for robustness and innovation,” adds Cheng.
Read more: How scientists are developing the crops of the future
Creating a genomic variation map
Maintaining the wheat collection was a truly gigantic effort: the seeds had to be planted, grown and collected again at least every 5 years. Of the 1000 landrace varieties Watkins collected from European, Asian and North African countries, 827 survived until the study, which began 12 years ago, was carried out.
The scientists carefully analyzed the wheat, whose genome is known to be five times larger than the human genome, and discovered that the Watkins wheat collection has 67 percent more genetic diversity than modern varieties.
“The Watkins wheat was harvested 100 years ago, but each variety of wheat has been grown and fed people for hundreds or even thousands of years,” Cheng explains. “They adapted well to the local environment, were able to withstand environmental stresses, and remained a rich, untapped source of diversity.”
The team characterized and projected 137 characteristics of 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. Lost traits identified by the scientists include higher nitrogen use efficiency, slug resistance and resistance to pests and diseases.
“If we have a lot of diversity and a new disease comes along, there might be a strain that is fortunately resistant to that disease. That’s the ecosystem we need,” says Cheng. “We need the diversity so we can deal with unpredictable events.”
Read more: What exactly are ancient grains – and should you eat them?
Could wheat diversity fight world hunger?
Genetic diversity can make wheat more resilient and give global wheat production a better chance of recovering from diseases, pests, bacteria and climate change.
Scientists have already crossed 119 varieties from the Watkins collection with modern wheat, creating a new collection of 12,000 varieties that are currently stored at the John Innes Centre’s Germplasm Resource Unit and have been brought to China for further experimentation. But Cheng says there is still a gap to be filled between these results and modern breeders.
“We have tested the genetic and phenotypic effects,” Cheng explains. “But farmers don’t necessarily care about that. They may ask, ‘How can your work help me?’ To make a real-world impact, we need to build a link between scientists and farmers, between basic research and applied breeding, to communicate our results to farmers.”
With this mission in mind, the team created a free academic and Breeding Toolkit to help breeders put their findings into practice, but Cheng believes there is still a long way to go. Because their study involves a lot of data that needs to be processed, he is confident that artificial intelligence can support future efforts.
Ultimately, the Watkins collection offers a glimmer of hope for the development and use of more robust wheat varieties to feed the world’s growing population more sustainably.
Read more: How the ancient Maya practiced sustainable agriculture
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