Scientists to detail progress and challenges regarding global cassava threats

The world’s top cassava experts are gathering in Nigeria to report progress on developing new varieties of cassava with higher yield and nutritional content. The meeting will take place on March 14-16, at the International Institute of Tropical Agriculture (IITA), in Ibadan.

“Africa produces more than half of the world’s cassava — about 86 million tons from over 10 million hectares,” said Chiedozie Egesi, IITA-based project manager of the Next Generation Cassava Breeding (NextGen Cassava) project, who also works to biofortify cassava with essential micronutrients. “But disease pathogens and climate change threaten cassava production and jeopardize the income and food security of smallholder farmers. Since 2012, scientists on the NextGen Cassava project have been working to significantly increase the rate of genetic improvement in cassava breeding and unlock cassava’s full potential.”

Cassava is a clonally propagated crop and seed set is difficult. New varieties with enhanced productivity and nutritional traits typically take up to 10 years to develop.

Scientists on the NextGen project are focused on giving breeders in Africa access to the most advanced plant breeding technologies to deliver improved varieties to farmers more rapidly.

“Partners of NextGen Cassava are using a state-of-the-art plant breeding approach known as genomic selection to improve cassava productivity for the 21^st century,” said Ronnie Coffman, Cornell professor of plant breeding and genetics, director of International Programs, who is the principal investigator on the multi-partner grant.

Genomic selection shortens breeding cycles, provides more accurate evaluation at the seedling stage, and gives plant breeders the ability to evaluate a much larger number of clones without the need to plant them in the target environment. Using genomic selection, new releases of cassava are ready in as little as six years.

“The best clones from NextGen Cassava genomic selection efforts are in Uniform Yield Trials this year and are due to be released to farmers in the next two years,” said Egesi.

Cassava is predicted to be one of the few crops that will benefit from climate change because it requires few inputs and can withstand drought, marginal soils and long-term underground storage. A cash and subsistence crop, the storage roots of this perennial woody shrub are processed, consumed freshly boiled or raw, and eaten by people as well as animals as a low-cost source of carbohydrates. No other continent depends on cassava to feed as many people as does Africa, where 500 million people consume it daily.  “The purpose of NextGen Cassava project is to improve the cassava breeding process making it faster and more efficient to produce the varieties farmers need,” said Peter Kulakow, cassava breeder at IITA, Ibadan.

In 2012, the Bill & Melinda Gates Foundation and the Department for International Development of the United Kingdom (DFID) under its UK Aid program invested $25.2M to improve the staple crop’s productivity and build human and technical capacity for plant breeding in sub-Saharan Africa.  

The five-year project, led by Cornell University, works with 10 institutional partners across six countries on three continents: Boyce Thompson Institute (BTI/USA), Embrapa (Brazil), International Center for Tropical Agriculture (CIAT/Colombia), International Institute of Tropical Agriculture (IITA/Nigeria), National Crops Resources Research Institute (NaCRRI/Uganda), National Root Crops Research Institute (NRCRI/Nigeria), University of Hawaii (USA), U.S. Department of Agriculture-Agricultural Research Service, and U.S. Department of Energy Joint Genome Institute. Most recently, NextGen Cassava has expanded to include Tanzania, partnering with the Lake Zone Agricultural Research and Development Institute (LZARDI).

The partners share cassava data, expertise, and information on a publicly available website (www.cassavabase.org).

In addition to reporting on the latest genomic information from cassava sequencing to improve productivity and yield, project partners will discuss progress on incorporating cassava germplasm diversity from South America into African breeding programs, training the next generation of plant breeders, and improving infrastructure at African institutions.