Cassava | St. Louis Public Radio

Cassava

Michael Okello arranges his cassava harvest, untouched by viruses.
File photo | Durrie Bouscaren | St. Louis Public Radio

To prove that a new-gene editing technology could be used to alter the cassava plant, scientists in the St. Louis suburbs zeroed in on a gene used to process chlorophyll. Before long, they had petri dishes full of seedlings that were white as chalk.

The plan is to use CRISPR — a cheaper, faster way to genetically modify crops — to grow cassava plants that are resistant to common plant viruses threatening food supplies in East Africa. But regulatory agencies have yet to finalize how they will treat the new crops.

“It’s only really been available for use in plants for three, four years,” said principal investigator Nigel Taylor, of the Donald Danforth Plant Science Center in Creve Coeur. “Right now, it’s an experimental tool.”

A cassava micro plant, grown in a Petri dish, is kept in a Danforth unit similar to a walk-in incubator.
File photo |Durrie Bouscaren | St. Louis Public Radio

Researchers at the Donald Danforth Plant Science Center say a $10.45 million grant from the Bill and Melinda Gates Foundation will allow them to expand a project to develop genetically modified cassava into Nigeria.

The country is the largest cassava producer in the world, and farmers there are watching closely as two plant viruses spread across central Africa. One of them, the brown streak virus, was once confined to coastal regions in southeast Africa. Strains of cassava that are genetically modified to resist the two viruses are undergoing field trials in Uganda and Kenya.

A Ugandan farmer holds a cassava root for sale in his stall
Durrie Bouscaren | St. Louis Public Radio

At the Gulu Main Market in northern Uganda, there’s an entire aisle devoted to cassava vendors.

For Ugandans, the starchy tuber is more than a staple food crop. It helped people survive many years of war. A project led by the Danforth Plant Science Center in Creve Coeur to develop genetically modified cassava is undergoing field trials in East Africa.

Botanist Nigel Taylor checks the stems of cassava plants at the Donald Danforth Plant Science Center in Creve Coeur.
File photo | Durrie Bouscaren | St. Louis Public Radio

As botanist Nigel Taylor moves through a greenhouse kept to 90 degrees Fahrenheit and 80 percent humidity, he checks the stems of young, potted cassava plants.

“You can see it there, OK?” Taylor said, pulling one forward. “We’re getting lesions on the stem, this plant’s quite badly infected.”

Call it manioc, tapioca or cassava — this starchy, tropical tuber feeds millions of people around the world. In many parts of East and Central Africa, farmers are experiencing declining yields of cassava due to brown streak virus, a plant disease that can render a crop inedible.

For the past decade, scientists at the Donald Danforth Plant Science Center in Creve Coeur have led a project that tries another tack: genetically modifying cassava plants for disease resistance.

(via Flickr/Intenational Center for Tropical Agriculture)

The Bill and Melinda Gates Foundation has given the Donald Danforth Plant Science Center in Creve Coeur $8.3 million to increase the nutritional value of a staple crop in Africa.

Danforth Plant Science Center is still growing after a decade

Sep 26, 2008

This article first appeared in the St. Louis Beacon: September 26, 2008 - This Sunday, Sept. 28, the Donald Danforth Plant Science Center celebrated its 10th birthday with tours, games, science demonstrations, music and, of course, cake. Opening the greenhouses to the community, the center's employees invited everyone to explore the center and see the progress made toward achieving its mission -- to improve the human condition through plant science.

Richard Sayre
Courtesy of the Danforth Plant Science Center

This article first appeared in the St. Louis Beacon: September 12, 2008 - Richard Sayre always wanted to be a scientist.

"I was a nerdy little kid," he says laughing and recalling an early foray into renewable energy production. In high school, he and his father built a device they hoped would generate an electrical current when heated, almost like a solar-powered battery. For the first test run, they put it in an oven, rigged up a way to measure current, and flipped the switch.

This post first appeared in the St. Louis Beacon: August 4, 2008 - Cassava. Sorghum. These plant names may be unfamiliar to most of us, but to nearly a billion people in the developing world cassava and sorghum are the food crops that stand between them and starvation.