MoBot scientists use DNA testing to bring an African plant out of extinction | St. Louis Public Radio

MoBot scientists use DNA testing to bring an African plant out of extinction

Jan 9, 2018

DNA technology has helped scientists discover a species of plant in Madagascar that’s long been classified as extinct.

The Missouri Botanical Garden reported Monday in the journal Oryx that researchers found a few populations of the Dracaena umbraculifera. It’s classified as extinct by the International Union for Conservation of Nature’s Red List, but there are specimens living in botanical gardens around the world. Identifying the plant, however, can be tricky because it can only be truly identified by its flowers. It has not flowered in any botanical garden.

The plant, which produces long leaves and a cluster of white and red flowers, was first documented in 1796 by botanist Nicolaus Joseph von Jacquin, who said the plant originated from Mauritius, an island in the Indian Ocean. Genetic testing showed that the plant is actually more closely related to plants in Madagascar than in Mauritius.

“We started to think that the species is actually from Madagascar,” said Christy Edwards, a geneticist at the Missouri Botanical Garden.

Missouri Botanical Garden geneticist Christy Edwards analyzed the genes of a rare plant in Madagascar, Dracaena umbraculifera.
Credit Missouri Botanical Garden

Edwards began analyzing the plant four years ago. While collecting samples in Mauritius, she met a resident who owned a flowering Dracaena umbraculifera.

“This was the only one that’s been observed as flowering in like 200 years and we knew this one had been correctly identified, so we used that as a reference,” Edwards said.

The gardener noted that he had acquired it from northeastern Madagascar.

Later, Jim Miller, senior vice president of research and conservation at the Missouri Botanical Garden, and his colleagues found several populations of the plant in that region during an expedition.

“All of the gardens that are currently growing this plant...nobody can tell you where they got it from,” Miller said. “But because the plant’s got DNA and these plants are all related to one another, we can show that. Even though we don’t have good documentation, we were able to make a good detective story out of this and figure it out.”

Edwards also learned that the plant labeled as Dracaena umbraculifera in the Missouri Botanical Garden’s Climatron dome was misidentified. It was actually a common houseplant called Dracaena reflexa, better known as the song of India.

Jim Miller, senior vice president of research and conservation at the Missouri Botanical Garden, stands next to a Dracaena umbraculifera in northeastern Madagascar.
Credit Missouri Botanical Garden

Researchers estimate that there could be as many as 14,000 plants in Madagascar. New discoveries are being made in the country, which is the size of California. At the same time, the island also suffers from rampant deforestation.

“There’s tons of diversity in Madagascar. It is going through a huge environmental crisis,” Edwards said. “I think [this study] highlights how important it is for there to be researchers and biologists, just cataloging the diversity and trying to make discoveries about Madagascar before it’s too late. I’m concerned that things will go extinct before we know they exist.”

MoBot scientists will lobby for the species to be upgraded to “critically endangered” on the IUCN’s Red List. Those working on conservation programs in Madagascar also will conduct outreach to educate local residents about the plant.

“In several places in Madagascar, we’d been able to teach people when a rare plant grows around their village that that’s their plant and nobody else has it. They get real proud of it and they start taking care of it,” Miller said. “My guess is, five years down the line, we will have the people that live where this plant is growing. They’ll all want to grow it in their yard, they’re all going to want to show it off.”

 

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