Crop Biotech Update

International Team Completes First Draft of Cassava Genome

November 13, 2009

An international research consortium announced that they have completed the first draft of the cassava genome, an important step in boosting research efforts to develop improved varieties of the subsistence crop. The team, led by the researchers at the University of Arizona, used a combination of Sanger paired-end and high-throughput 454 single and paired-end sequencing to complete the draft of the 760 Mb cassava genome.

Cassava is a staple food for more than 750 million people mainly from the developing world. It is a hardy crop capable of withstanding a variety of environmental conditions including drought. However, the crop is susceptible to many diseases, including the dreaded Cassava Brown Streak Disease (CBSD) which is currently threatening the food security in some parts of Africa.

The cassava sequencing project, which started in 2003 with the formation of the Global Cassava Partnership (GCP-21), gathered momentum earlier this year when 454 Life Sciences and the US Department of Energy Joint Genome Institute (DOE JGI) pledged the resources to use 454's Genome Sequencer FLX platform to rapidly generate the DNA sequence data needed.

More than 61 million sequencing reads were generated and assembled into a draft genome which according to the scientists covers 95 percent of the cassava genes (416 Mb of the 760 Mb cassava genome). "The information contained in the cassava genome will provide tremendous opportunities to improve this important crop, bringing it into the mainstream of plant research thereby reducing the time and cost of delivering improved cultivars to farmers who need it most," said Claude Fauquet of the Donald Danforth Plant Science Center.

Building upon the newly available cassava genome, the Bill and Melinda Gates Foundation awarded the University of Arizona with a USD 1.3 million grant to develop additional genetic resources for cassava. The resources will provide breeding tools, such as genetic markers for important traits, to aid farmers in improving the important crop.

Read the original story at http://www.danforthcenter.org/newsmedia/NewsDetail.asp?nid=182 The genome sequence is available at http://www.phytozome.net/cassava