Possible benefits of deciphering cassava's genetic code include not only improving it as an agricultural crop but also boosting its potential for fuel ethanol in developing countries. Above, Ghanaian women peel cassava, a food staple for more than 600 million people in Africa, Asia and Latin America. Image courtesy Food and Agriculture Organization of the United Nations; photo FAO/18293/P. Conti.

Scientists Gear Up To Decode Cassava Genome

By Jan Suszkiw
August 30, 2006

Efforts to sequence the genome of cassava, a staple food for millions of people worldwide, could yield the genetic keys to unlocking new traits for improved yield, more protein and even novel industrial applications—like putting fuel in the gas tank.

That’s the hope of Agricultural Research Service (ARS) scientists James Anderson and David Horvath, members of a 10-institute team that will sequence and annotate the cassava genome starting this fall. The U.S. Department of Energy’s Joint Genome Institute is providing funding and technical assistance.

Anderson and Horvath, both with the ARS Plant Science Research Unit in Fargo, N.D., envision comparing cassava’s genome with that of leafy spurge, a close relative that's an invasive perennial weed in 35 states. Key differences resulting from such comparison could foster new ways of increasing cassava’s stress tolerance and disrupting leafy spurge’s shoot growth. Genomic information from cassava could also expedite research to re-establish castor bean, another close relative, as a domestic source of industrial oil, minus the toxin ricin.

Globally, the benefits of cassava genome sequencing could materialize as new higher- yielding or more pest- and disease-resistant cultivars. Of particular interest is coaxing more protein from cassava to better supplement the dietary needs of more than 600 million people in Asia, Africa and Latin America who rely on the crop as a main source of calories.

On the industrial front, ratcheting up cassava’s starch production under a wider range of conditions could set the stage for developing countries to use the crop for making fuel ethanol. Indeed, cassava can maintain high productivity under conditions that cause other crops to fail, including corn, whose starch costs more.

Together with principal investigator Claude Fauquet of the Donald Danforth Plant Science Center in St. Louis, Mo., Anderson is assisting with the examination of 25 different cassava cultivars to determine which are best suited to the first stage of sequencing. This will cover a portion of cassava’s total genome—500 megabase pairs—with the rest to follow, pending a successful outcome.

ARS is the U.S. Department of Agriculture's chief scientific research agency.