Seeds from 400 wild relatives of food crops such as bananas, rice and aubergines have been collected to save their valuable genetic diversity before it is lost. These could be crucial for maintaining food production as the climate changes.
“This was a massive effort,” says Hannes Dempewolf at the Crop Trust in Bonn, Germany, which led the 10-year project. The next step is to use the wild plants to breed new varieties of crops with traits such as drought or disease resistance.
That is important because we know that if farmers keep cultivating the same varieties in the same way, yields can plummet as pests and diseases evolve and spread. For instance, rice yields in Asia were hit by the rice grassy stunt virus in the 1970s, says Dempewolf. Resistant varieties were then created by crossing rice with a wild relative. Now the virus is becoming a problem again. It is a constant battle, a bit like walking up an escalator the wrong way.
What is more, the speed at which such issues arise is accelerating because of climate change, which is already hitting food production. “You have to walk faster to stand still,” says Alisdair Fernie of the Max Planck Institute for Molecular Plant Physiology in Germany, who wasn’t involved in the project.
This is why the Crop Trust set out to save the genetic diversity present in wild plants. “Since 2013, more than 12 million seeds have been collected,” says Chris Cockel at Kew’s Millennium Seed Bank in the UK. These come from about 5000 locations of the 400 crop relatives.
Plants sampled include a wild relative of the carrot, one that grows in salty water, an oat relative resistant to the powdery mildew that devastates normal oats, and a kind of bean that tolerates high temperatures and drought.
The seeds are now being sent to non-profit breeding organisations around the world. Some will also be stored in seed banks, including the Svalbard Global Seed Vault in the Arctic.
In some cases, the collectors arrived in the nick of time. In Ethiopia, samples were taken from a region that will soon be flooded by a dam. In Chile, they found only one site where a wild barley was still growing after a massive fire destroyed most of its habitat.
Sometimes they were too late. In Costa Rica, collectors found only sugar cane plantations and urban sprawl where a wild rice used to grow.
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“We have made incredible progress,” Marie Haga, director of the Crop Trust, said in a statement. “But there is more to be done, and as threats to the world’s biodiversity mount, this work is more urgent than ever.”
As well as improving existing crops, we should also be conserving and domesticating wild plants that are rarely grown and eaten, says Fernie. At present the world is over-reliant on a handful of crops, some of which are grown where conditions aren’t ideal.
In these places, domesticating local plants – which can now be done very rapidly – could allow more food to be grown in a more sustainable way. But for farmers to diversify the plants they grow, consumers will have to diversify their diets.
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