“Late blight” is an old enemy of humans. This disease catalyzed the devastating Irish potato famine that began in 1845.
It is caused by a fungus-like pathogen, which quickly kills the potato plant and turns the crop into inedible mush.
More recently, late blight has been infiltrating the higher parts of the Peruvian Andes, as warmer, wetter weather helps the pathogen spread.
That’s why scientists at the International Potato Center (CIP), a research institute in Peru, have been highly motivated to develop potato varieties that can resist late blight.
They looked for this trait among the crop’s so-called wild relatives: undomesticated plants that are distantly related to those now grown for food.
After finding resistance to the disease in wild relatives of the potato, they crossed the wild plants with cultivated plants. Local farmers then tested the newly developed varieties and voted for which ones they preferred to grow, sell and eat.
The result is CIP-Matilde, a potato variety released in 2021 that does not require fungicides to resist late blight.
“It is usually easier to improve resistance to a given disease,” explains Benjamin Kilian, senior scientist at Crop Trust, based in Bonn, Germany.
The nonprofit partnered with CIP to develop the Matilde potato and is working on many other crop varieties.
While disease resistance can be reduced to a single gene, creating resistance to stressors such as drought or salinity can involve working with hundreds of genes.
To address drought tolerance, for example, scientists could explore traits such as early flowering to escape the effects of drought, less water loss from plant leaves, or long roots so plants can spread further. to reach the water.
Kilian leads the Crop Trust’s Biodiversity for Opportunities, Livelihoods and Development (Bold) project, which brings together partners including community seed banks, national breeding programs and international research centres.
The most important thing is that it also brings together farmers. They express their preferences for particular traits and test the different varieties of crops in development (which includes voting by placing stones, sticks or seeds next to their favorite varieties).
These participatory processes involve listening to different types of farmers, says Kilian.
For example, “sometimes women and men, even within the same family, prefer different characteristics.”
Women may be more concerned with taste and nutrition, while men tend to focus more on performance.
Yield (the amount of a crop actually harvested per unit of land) is never far from conversations about agricultural production.
However, trying to maximize yield at all costs has led to a more monotonous food system, with high-yielding varieties crowding out many others.
“Under optimal conditions and with a high level of inputs, high yields can be achieved. But there is also the risk of completely losing the harvest,” says Kilian.
“For most farmers, it is more important to have stable, reliable performance in all kinds of different environments.”
One crop that the Bold project supports is the pea (also called peas). Kilian explains that this nutritious legume can withstand waterlogging and harsh environments.
“It was often the last crop to survive if there was a drought.”
It fell out of favor due to a toxic compound that could be dangerous if ingested in large quantities (such as during a famine). But the Crop Trust and its partners are working to reduce toxicity by crossing peas with wild crop relatives.
Another forgotten crop that scientists highlight for its resilience is azolla (water fern), a fern that grows surprisingly fast and doesn’t require much water.
And the wild tepary bean can withstand the harsh conditions of the desert.
precise tool
Breeding traditional crops can be time-consuming and laborious.
Brad Ringeisen, executive director of the Institute for Genomic Innovation (IGI) at the University of California (Berkeley and San Francisco), believes that gene editing using tools like Crispr-Cas9 is the most impactful way to ensure that crops can resist disasters.
“Accelerates innovation cycles. It is a precise tool.”
Ringeisen summarizes the IGI’s work on crop disease resistance: “There are a huge number of emerging diseases and climate change is not helping.”
He says gene editing is a better way to tackle diseases than spraying more pesticides.
In addition to disease resistance, IGI works on drought tolerance.
A variety of rice that has been genetically edited to reduce the number of pores in the leaves, thus reducing water loss, is now in field trials in Colombia.
These tests are necessary to ensure that genetic edits do not cause unforeseen side effects in practice.
The IGI project is one of several scientific efforts to make rice less vulnerable to unpredictable water cycles.
Scientists at the International Rice Research Institute in the Philippines, for example, developed a variety of “submarine rice” that can withstand weeks of immersion in water during floods.
Sometimes the technological process takes longer to ensure that genes from other species are not added.
This genetic modification remains highly restricted in the European Union, which is a challenge for the commercial viability of genetically modified organisms (GMOs).
By comparison, gene editing involves removing small sections of DNA, in an acceleration of processes that could have occurred naturally (over a much longer period of time).
Gene-edited crops are now legal in countries like England and Kenya.
“In many cases they are simply deleting a gene,” Ringeisen says of gene editing systems. “There is no foreign DNA.”
Gene editing has already developed rapidly. But one young seed design company that wants to take the technology even further is Massachusetts-based Inari.
Instead of editing a single gene at a time, multigene editing allows you to target multiple genes at once.
This may be beneficial given the increasingly complex interrelationships of climate threats, where a crop may be under multiple types of stress at the same time.
For now, the focus of Inari’s multiple gene editing, combined with AI-assisted predictive design, is on performance.
The company aims to increase performance by 10 to 20 times. Unlike Crop Trust, Inari focuses on three powerhouse crops: corn, soybeans and wheat.
Ponsi Trivisvavet, CEO of Inari, says its soybeans are close to commercialization. Initially, the company is targeting the Australian and United States markets.
Although there are many critics of agricultural intensification with monocultures, Trivisvavet believes that being able to produce more crops with the same amount of resources is beneficial for a changing climate.
“It’s about reducing water and fertilizer per bushel,” he says.
One concern with hybrid and genetically edited plant varieties is their affordability for farmers.
While legal frameworks vary, farmers often have to continue purchasing new seeds each planting season, rather than saving them.
Organizations like the African Center for Biodiversity are demanding that seed management remain in the hands of farmers, rather than companies that can patent seeds.
Climate change is likely to force many people to change their diets, and prized crops such as cocoa and bananas are already proving vulnerable to climate pressures.
Taking advantage of the variety within these crop families and others could help.
“I think we should all value crop diversity. We cannot depend on just a few important crops,” Kilian warns.
Keep reading:
* Why are fish getting smaller and smaller? Believe it or not, this affects us
*This is how climate change will transform our eating habits
*Has it ever been as hot as it is now?
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