Team Seeks to Improve the Black-Eyed Pea

[February 19, 2008]  CHARLOTTESVILLE, Va. (AP) -- A team of University of Virginia researchers is working to increase the drought- and disease-resistance of the black-eyed pea, a staple of the diets of roughly 200 million people in west and central Africa.

The U.Va. scientists are working with African growers to produce a tougher version of the legume, also known as the cowpea. About 80 percent of the 3 million tons of cowpeas produced worldwide each year originate in west and central Africa.

"Cowpea is kind of the soybean of Africa," said Michael Timko, the U.Va. biologist leading the Cowpea Genomics Initiative. "For west Africa and most of sub-Saharan Africa, it's the main protein in their diet."

Africans also consume the plants' leaves like kale or spinach, and their cattle frequently eat the stems.

But the legume is highly susceptible to drought, insects and parasitic weeds, especially a particularly deadly one called witchweed. In many fields, these hazards have reduced cowpea production, and in extreme cases they've altogether wiped out crops.

The Cowpea Genomics Initiative aims to minimize these threats by combining modern molecular-based technology with traditional selective breeding techniques.

As part of the project, 25 African scientists have visited the U.Va. lab.

Over the past two years, Timko and other U.Va. researchers have mapped out the cowpea's genetic sequence. Their results will be published in an upcoming issue of the scientific journal BMC Genomics.

"With this research, we can add a lot of value to global humanitarianism and African development," said Xianfeng "Jeff" Chen, a U.Va. professor of microbiology involved in the cowpea genetic sequencing.

The mapping process, he said, had a running start because cowpeas' DNA structure is very similar to that of soybeans, which U.S. geneticists have studied for years. Consequently, the U.Va. researchers were able to build on the existing soybean research and help the African growers more quickly, Chen said.

Now the researchers are identifying genetic markers that might control cowpea traits such as drought resistance, nutrition content, and disease and parasite resiliency. Once characteristics are identified, the researchers' genetic map allows growers to speed up the traditional selective-breeding process and quickly produce a stronger cowpea.

A cowpea variety that is resistant to witchweed -- officially known as striga -- was developed in Timko's lab and is already being introduced in African fields. Striga is notoriously tricky to control because so much of its damage occurs underground, as the parasite anchors itself to the host plant's roots and sucks out energy and nutrients.

In addition to beefing up the cowpea's striga defense, the U.Va. researchers also hope to make other genetic enhancements to cowpea varieties as the initiative moves forward.

"It's good to be able to do research that is not only answering an interesting scientific question: 'What makes plants resistant to parasites or drought?' But it's also helping to secure a food source for people," Timko said.

[Associated Press]

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