Distant Cousins Of Food Crops Deserve Respect And Protection

Dec 16, 2020
Originally published on December 16, 2020 8:22 am

Hundreds of native North American plants, often dismissed as weeds, deserve a lot more respect, according to a new study. These plants, distant cousins of foods like cranberries and pumpkins, actually represent a botanical treasure now facing increased threat from climate change, habitat loss and invasive species.

The crops that the human race now depends on, including grains like wheat and tree fruit like peaches, originally were selected or bred from plants that grew wild hundreds or thousands of years ago. And those ancestral plants, like the small wild sunflowers that can be found across the United States, still exist. "If you see them growing along roadsides, those are the ancestors," says Colin Khoury, a research scientist at the International Center for Tropical Agriculture.

In the U.S., there are wild ancestors of blueberries, sweet potatoes, onions, potatoes, and many other food crops. Some of them are quite common. Khoury says wild lettuce plants grow along sidewalks, or in backyards, but go unrecognized. "They look nothing like lettuce," he says. "They're scratchy and thorny and little and ugly."

Other crop relatives are rare and threatened. One of Khoury's favorites is called the paradoxical sunflower. It "grows just in wetlands of the deserts of New Mexico and Texas. Little salty seeps where there's a little bit of water beneath the soil," he says.

Khoury loves these wild relatives of food crops, and not just for sentimental reasons. "These wild plants are valuable," he says.

That paradoxical sunflower, for instance, can survive in a salty environment that would kill most plants. So plant breeders cross-pollinated it with commercial sunflowers and created new varieties that can grow in places where the soil contains more salt.

Other wild relatives may be hiding similarly remarkable gifts, Khoury says, such as genes that could help their domesticated relatives survive diseases, deal with pests, or adapt to disruptions in the climate.

Khoury and some of his colleagues just finished a survey of about 600 wild crop relatives that grow in North America, and published it this week in the Proceedings of the National Academy of Sciences.

They found that most of these plants are threatened from things like fires, farming and development. The scientists argue that they deserve more protection. For one thing, "gene banks" which preserve seeds in refrigerated vaults should collect and preserve them. In addition, these plants need more protection in their natural habitat.

According to Khoury, that doesn't necessarily mean setting aside land for them. In many cases, the plants already are growing on public land that's managed by the U.S. Forest Service or the Bureau of Land Management.

"It's more just being aware that these plants actually exist," he says. "They're not particularly on the radar of large organizations like the Forest Service.

In that regard, there's been some progress. The Forest Service is now cataloguing wild cranberries on its land in the southeast, as well as wild chile peppers in Arizona, along the border with Mexico.

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STEVE INSKEEP, HOST:

We have news of some weeds in your yard or in a park near you. Apparently, some weeds deserve a lot more respect. A new study calls these native plants a botanical treasure. They are distant cousins of crops that we eat like cranberries and pumpkins. NPR's Dan Charles has the story.

DAN CHARLES, BYLINE: All the crops that farmers now grow are derived from plants that grew wild hundreds or thousands of years ago. And Colin Khoury, who works at the International Center for Tropical Agriculture, says the wild versions are still out there.

COLIN KHOURY: If you see them growing along roadsides, et cetera, those are the ancestors.

CHARLES: In the U.S., there are wild ancestors of blueberries, sweet potatoes, onions, potatoes, lots of crops. Some of them are common. Khoury says you may walk past wild lettuce plants growing along sidewalks and never recognize them.

KHOURY: They look nothing like lettuce. They're scratchy and thorny and little and ugly.

CHARLES: Other crop relatives are rare and threatened. One of Khoury's favorites is a wild sunflower.

KHOURY: The paradoxical sunflower grows just in wetlands in the deserts of New Mexico and Texas, little, salty seeps where there's a little bit of water beneath the soil.

CHARLES: Khoury loves these wild relatives of food crops and not just for sentimental reasons. Take that paradoxical sunflower. It can survive in a salty environment. So plant breeders cross pollinated it with commercial sunflowers and created new varieties that can grow in places where the soil's more salty. These wild relatives may be hiding all kinds of special gifts, Khoury says, maybe genes that could help crops survive diseases or deal with pests or climate disruption.

KHOURY: So these wild plants are valuable.

CHARLES: Khoury and some of his colleagues just finished a survey of about 600 wild crop relatives that grow in North America. They published it this week in the journal PNAS. They found that most of these plants are threatened from things like fires, farming and development. Khoury says so-called gene banks should collect and preserve them. But also, these plants need more protection in their natural habitat. That doesn't necessarily mean setting aside land for them, he says. In many cases, the plants already are growing on public land.

KHOURY: It's more of being aware that these plants actually exist. They're not particularly on the radar of the land managers of large organizations like the Forest Service.

CHARLES: There's some progress, though. The U.S. Forest Service is now conserving wild cranberries on its land in the Southeast and wild chili peppers in Arizona along the border with Mexico.

Dan Charles, NPR News.

(SOUNDBITE OF TOMMY EMMANUEL'S "WAITING FOR A PLANE") Transcript provided by NPR, Copyright NPR.