Wild relatives of wheat, humanity's most widely grown crop, could provide a solution to adapting to the climate crisis.
Farmers face unpredictable rainfall patterns, droughts, heat waves, and flooding as extreme weather becomes more frequent and destructive due to the climate crisis. However, a combination of soil degradation and the climate emergency limits Africa's potential to be the world's food powerhouse with millions of hectares of fertile soil. The continent witnessed a decline in the consumption of traditional foods as society and agriculture evolved, contributing to a loss of dietary diversity.
According to studies, 90% of the world's food comes from just 20 plants, and three - wheat, maize, and rice - account for 60% of all calories consumed. Given the global threat to important wheat-growing areas from wheat blast, a devastating disease caused by the fungus Magnaporthe oryzae pathotype Triticum This may force farmers to shift to less susceptible crops to mitigate production and financial losses.
A new study from the International Maize and Wheat Improvement Center (CIMMYT) suggests ancient wild relatives of wheat may hold the key to climate-proofing global food security by providing essential genetic traits.
Modern wheat breeding programs often rely on disease resistance genes from wild relatives
"Wheat is the most widely grown crop on Earth, providing 20% of all human protein and calories," said Dr Matthew Reynolds, Head of Wheat Physiology and Distinguished Scientist at CIMMYT.
He said wheat is the primary staple food for 1.5 billion resource-constrained people in the Global South. However, like any crop, wheat is vulnerable to natural enemies, especially fungal diseases that evolve so rapidly that new varieties must be introduced every few years as virulent strains spread swiftly through the wind and jet stream. "Modern wheat breeding programs often rely on disease resistance genes from wild relatives, which have already prevented devastating epidemics and even a potential pandemic of 'stem rust' that threatened all wheat cultivars worldwide," said Dr Reynolds.
"Since 2000, this strategy has likely spared the use of about a billion litres of fungicide - just one of many environmental benefits. These wild genes have also improved grain yield and nutritional value, enhancing livelihoods and conserving millions of hectares of natural ecosystems from cultivation."
About 13% of global wheat production will be reduced due to wheat blast by 2050.
Key to Crop Resilience?
Global genebanks preserve an array of genetic diversity, but only a small fraction is harnessed for modern wheat breeding. To strengthen crop resilience against climate change, researchers use phenotyping and genomics to identify drought-resistance traits from wild wheat relatives.
Dr Reynolds said while crops were developed relatively recently in evolutionary terms, limiting their ability to interbreed with wild relatives, these wild relatives "survived adverse environmental conditions for millions of years." This resilience makes them invaluable for adapting modern wheat to new disease strains and other environmental challenges in the coming decades - far outweighing the investment needed for large-scale screening of wild relatives and ancient landraces.
"Wild relatives can be screened under specific drought scenarios to identify lines with adaptive growth responses, and selected lines are then crossed with elite wheat lines using specialized techniques to create novel elite varieties containing drought-adaptive genes."
This process is enhanced by state-of-the-art technologies: remote sensing measures plant responses in both wild relatives and new wheat lines, identifying those benefiting from stress-adaptive genes; deep sequencing helps discover drought tolerance genes and identify markers to track them in breeding pipelines; and new insights into crop ecology, both above and below ground, reveal the importance of symbiosis with the microbiome.
The probability of success and return on investment is likely very high
Dr Reynolds said there has "never been a more opportune moment" to systematically explore crop wild species, where "hidden treasures" wait to be discovered.
"The probability of success and return on investment is likely very high. The impacts of exploring even a small fraction of the 800,000 wild relative lines in storage have significantly increased and protected wheat productivity, adding at least hundreds of billions of dollars in value over baseline since 2000," he said.
"Crop and climate modeling indicates that wheat output in Africa will be severely affected by climate change. In addition, there are large yield gaps across most wheat-producing regions in Africa," said Dr Reynolds. "These yield gaps between potential and actual yields can be addressed through improved seed varieties, modernization of irrigation infrastructure, and integrated policies that include adequate, well-coordinated long-term investment to support the entire wheat value chain."
Climate-Smart, Nutrition-Rich
Climate-smart agricultural practices must be implemented, crops diversified, soil and water management improved, and local governance and infrastructure strengthened to ensure food security in sub-Saharan Africa and adapt agriculture to climate change.
"Crop research - including into wheat wild relatives - needs systematic investment and translation to breed where modern technologies can accelerate progress ... national variety testing infrastructure can be improved ... and small-scale farmers need credit to invest in new seed and crop management practices conducive to symbiosis with the microbiome."
"In terms of nutrition, wheat has been biofortified using genes from exotic relatives and lines have been released already in South Asia and can be tested in Africa for release," Dr Reynolds said.
Crop wild relatives provide essential traits for developing resilient farming practices that can withstand climate change, pests, and diseases, ultimately ensuring food security and biodiversity conservation. Therefore, their diversity is crucial for the future of agriculture.
This resilience makes them invaluable
Climate scientists have warned of the grave risks posed by increasingly frequent extreme weather events, such as heat waves, cold snaps, delayed rains, flooding, and warm nights, he said, and rising temperatures also heighten the threat from insects, pathogens, and weeds, with chemical control costs amounting to a staggering U.S.$1.4 trillion annually - 5% of global GDP - as well as the incalculable damage to biodiversity and the environment.
Dr Reynolds said while crops were developed relatively recently in evolutionary terms, limiting their ability to interbreed with wild relatives, these wild relatives "survived adverse environmental conditions for millions of years." This resilience makes them invaluable for adapting modern wheat to new disease strains and other environmental challenges in the coming decades - far outweighing the investment needed for large-scale screening of wild relatives and ancient landraces.
"One of the most exciting recent developments in biology is the discovery of the role of microorganisms 'the micro-biome', in plant and animal health," he said. "This offers immense opportunities to enhance the productivity and resilience of our cropping systems while reducing their environmental impact, provided the crop environment is adapted to foster these beneficial interactions.
Genebanks are one of the best ways to preserve and provide access to seeds
*Microfauna, found on leaves and underground, play crucial roles in fighting off pests and diseases, increasing nutrient availability, and maintaining root health. Some studies even suggest benefits in terms of drought and heat tolerance. Breeding new crop varieties that foster positive synergies with micro-organisms will be crucial for advancing future cropping systems.
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"Over eons, wild relatives have likely developed multiple symbiotic relationships with the microbiome, offering numerous opportunities to enhance crops, reduce reliance on agrochemicals, and contribute to climate mitigation. The only crop bred to promote such microbiome interactions to date is wheat, through the wild grass Leymus racemosus (of the Triticeae tribe). This gene imparts a trait known as biological nitrification inhibition (BNI), which reduces greenhouse gas emissions and improves nitrogen use efficiency."
How Genebanks Will Shape the Future of Food
A genebank protects the world's food supply against the pressures of climate change and other threats to crops. The seed repositories ensure that healthy, stable, and diverse varieties of crops will be available when we are in need. Genebanks are one of the best ways to preserve and provide access to seeds that farmers and breeders can use in the long run to create improved crop varieties even decades after they have been collected. Genebanks play a vital role in preserving crop diversity and ensuring food security in the future. They serve as essential reservoirs of genetic material for developing resilient, adaptable crops. Ultimately, the climate crisis and population growth will pose challenges to food systems that need to be sustainable.
"Collection of crop wild relatives began a century ago and continues to this day," said Dr Reynolds. "Despite limited characterization, their impact on crop improvement has been remarkable and beneficial for the environment. However, political will is crucial to ensure the ongoing collection, storage, and availability of these wild relatives, which are essential for expanding crop diversity and 'future-proofing' crops."
"Without this commitment, large-scale crop failures could devastate society, disrupt commerce and geopolitical stability, and potentially lead to human migration, famine, and, as history has shown, war," said Dr. Reynolds.
