NAIROBI, Aug 26 (IPS) – Groundbreaking research suggests that wheat’s wild cousin could be transformed into a food security crop for all time, protecting vulnerable populations from hunger and starvation thanks to its ability to withstand both climate stress and disease. Wheat is a staple food for more than 1.5 billion people in the Global South.
The review looked at two different studies and found that harnessing the ancient genetic diversity of wild relatives of wheat, which provides 20 percent of the world’s calories and protein, could lead to weather- and disease-resistant varieties of the crop, which could ensure food security around the world.
The study led by the International Maize and Wheat Improvement Centre, a study finds that “long-overlooked” wild wheat relatives have the potential to revolutionise wheat breeding, with new varieties resilient to climate change and its associated threats, including heat waves, droughts, floods, and emerging and ongoing pests and diseases.
Relatives of wild wheat, which have endured environmental stress for millions of years, possess genetic traits that modern varieties lack. These traits, if incorporated into conventional varieties, could make wheat cultivation more viable in increasingly hostile climates, the study published today (August 26, 2024) explains.
Growing the most resilient wheat could increase productivity by an estimated $11 billion in additional grain per year, the authors said in the review article titled “Wheat genetic resources have avoided disease pandemics, improved food security and reduced the ecological footprint: a review of historical impacts and future opportunities‘ published by the journal Wiley Global Change Biology.
The review suggests that the use of plant genetic resources (PGR) helps against various diseases such as wheat rust and protects against diseases that cross species barriers such as wheat blast. It provides nutrient-rich varieties and polygenic traits that create climate resilience.
The study highlights a vast, largely untapped reservoir of nearly 800,000 wheat seed samples stored in 155 genebanks worldwide, including wild varieties and ancient farmer-developed varieties that have withstood multiple environmental stressors over the millennia. This is despite the fact that only a fraction of this genetic diversity has been used in modern crop breeding.
According to co-author Mathew Reynolds, the findings will have major implications for food security, particularly in the Sub-Saharan African region, home to the world’s most food insecure populations.
“The discoveries are very promising as Africa has many new environments in terms of potential wheat cultivation,” he told IPS.
Based on the research results, significant environmental benefits have been achieved through several scientific efforts that have successfully integrated wild genes into modern species.
The research shows that the use of PGR in wheat breeding has improved the nutrition and livelihoods of resource-limited farmers and consumers in the Global South, where wheat is often the grain of choice in parts of Asia and Africa.
“We’re at a critical point,” Reynolds says. “Our current breeding strategies have served us well, but they now need to address more complex challenges that climate change poses.”
He notes that breeding that helps maintain genetic resistance to a range of diseases improves ‘yield stability’ and prevents epidemics of devastating crop diseases, which ultimately threaten food security for millions of people.
“Moreover, genetic yield improvements after the Green Revolution are generally achieved with less (in the global North) and often no fungicide in the global South, and without necessarily using more fertilizer or irrigation water, except in a few high-production environments,” the study said.
As a result, grain yields have increased and millions of hectares of “natural ecosystems” have been saved from being cultivated for grain production. This includes millions of hectares of forests and other natural ecosystems, Reynolds and colleagues found.
Also promising is the discovery in several experimental wheat lines with wild traits that show up to 20 percent more growth under heat and drought conditions compared to current varieties, and the development of the first crop ever bred to interact with soil microbes that has shown potential in reducing the production of nitrous oxide, a potent greenhouse gas. This allows plants to use nitrogen more efficiently.
“The use of wild relatives of PGR, landraces and isolated breeding gene pools has had a substantial impact on wheat resistance to biotic and abiotic stresses, while increasing nutritional value, end-use quality and grain yield,” the study further found.
The study found that without the use of PGR-derived disease resistance, the use of fungicides to combat fungal diseases, the biggest threat to crop yield, would have easily doubled. This would have greatly increased selection pressure, driven by the need to prevent fungicide resistance.
Remarkably, it is estimated that one billion litres of fungicide use has been saved on wheat, saving farmers billions in the purchase and application of chemicals.
The authors note that as weather becomes more extreme, the crop breeding gene pool will need to be further enriched with novel adaptive traits derived from PGR to survive the vagaries of climate change.
These include ‘certainly’ stubborn diseases that plague wheat cultivation in the tropics, such as Ug99, a devastating stem rust fungal disease which, in the worst case, could wipe out entire crops in Africa and parts of the Middle East, Reynolds said.
Modern crop breeding, it says, has largely focused on a relatively narrow group star athletes— elite crop varieties that already perform well and whose genetics are known and predictable.
In contrast, the genetic diversity of wild wheat species offers complex, climate-resistant traits that are more difficult to harness because they are more time-consuming, expensive and riskier than traditional breeding methods used for elite varieties.
“We have the tools to rapidly explore genetic diversity that was previously inaccessible to breeders,” explains Benjamin Kilian, co-author of the report and coordinator of the Crop Trust’s Biodiversity for Opportunities, Livelihoods and Development (BOLD) project, which supports the conservation and use of crop diversity worldwide.
Tools include next-generation gene sequencing, big data analytics and remote sensing technologies, including satellite imagery. The latter allows researchers to routinely monitor traits such as plant growth rate or disease resistance at any number of locations worldwide.
Although PGR collection and storage has played an important role since the early 20th century, especially in breeding disease-resistant plant varieties, the study concludes that there is still enormous untapped potential.
Since wild relatives have survived millions of years of climate variation compared to our relatively recent crop species, more systematic screening is recommended to identify new and better sources of needed traits, not only for wheat but also for other crops, the study advises.
Calls are made for increased investment in research into resilient wild varieties of common crops, using widely available, proven and non-controversial technologies that have multiple impacts and provide substantial return on investment.
“As new technologies are continuously emerging that facilitate its use in plant breeding, PGR should be considered the best option for achieving climate resilience, including its biotic and abiotic components,” the authors said.
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© Inter Press Service (2024) — All rights reservedOriginal source: Inter Press Service
