By Gift Briton

Researchers have made a significant breakthrough expected to help advance the breeding of new cassava varieties faster and accurately after they successfully mapped the genome of African cassava, using the TME 204 variety resistant to Cassava Mosaic Disease-2 (CMD2).

According to Prof Wilhelm Gruissem, principal scientist of the research team, Department of Biology, Institute of Molecular Plant Biology, Swiss Federal Institute of Technology in Zürich (ETH Zurich), “The genome has a very high quality and accuracy, and the group of alleles inherited together from a single parent have been resolved with high confidence. It is now definitively the gold standard genome for African cassava. Our work has revealed several new and interesting features of the cassava genome that will be of importance for breeders and cassava scientists.”

Cassava is a vital food crop produced through asexual reproduction in tropical and subtropical regions with almost one billion people worldwide depending on it for food or raw materials.

In Africa, the crop is a major source of livelihood for smallholder farmers and a plug for food security owing to its ability to withstand a wide array of environmental conditions.

However, its production is constrained by weeds, drought, pests, and most crucially, viral diseases.  Therefore, breeding of more robust and productive cassava varieties is of high importance.

Furthermore, efforts to improve its performance and develop new varieties through genetic manipulation has been limited, partially because cassava has two different alleles for a specific trait with a repetitive and difficult-to-assemble genome.