An international team of researchers has mapped the entire genetic code of wild African rice in an effort to develop new “super rice” varieties that are better able to cope with increasing environmental stress and help solve global hunger challenges.
Until now, wild African rice had not been fully utilized in terms of all the different stress-tolerant traits it contains when hybrids were developed for cultivation. But, according to research published online in Nature Genetics July 28, rice production will soon be a whole lot easier.
“Once you identify genes that are associated with salt stress, heat stress, different types of pathogens, then you can select the optimal crosses to move forward to improve rice production in Africa, or other countries for that matter,” research leader Rod Wing, director of the Arizona Genomics Institute at the University of Arizona told AFKInsider.
According to Wing, this means being capable of crossing Asian and African rice species to develop all new varieties of rice with the traditional high-yield traits of Asian rice and the new-found hardiness traits of African rice.
The announcement came just before the Philippines-based International Rice Research Institute wrapped-up its latest rice production training session which ended on August 15 for African researchers from Benin, Burkina Faso, Congo, Cote d’ Ivoire, Kenya, Guinea, Mali, Tanzania, and Togo.
Super Rice?
Crossing Asian and African rice species – the only domesticated rice species – to develop more desirable hybrid varieties is not new. But until now these efforts have been limited.
“Not all the combinations have been made and the reason that we have a genome sequence is that we can now precisely identify the genes we want to cross with Asian rice,” Wing told AFKInsider.
For example, about 10 million of the poorest rice farmers in sub-Saharan Africa and South Asia have already been given access to climate-smart rice varieties, according to the International Rice Research Institute which helped to develop some of these hybrids.
The Institute’s Stress-Tolerant Rice for Africa and South Asia (STRASA) project, initiated in 2007 in collaboration with AfricaRice, has delivered several rice hybrids to the millions of farmers around the world, including 14 varieties in sub-Saharan Africa.
That global project is being funded with $32.8 million by the Bill & Melinda Gates Foundation for five more years.
But the rice varieties have been pretty much limited to high-yielding Asian-crossed varieties – known as NERICA or “New Rice for Africa” -with tolerance to flood and pest stresses. Rather than wild African rice, NERICA is the rice now cultivated in Africa.
“So, the rice you would be eating would be primarily of Asian rice genetic material over African genetic material,” says Wing.
It was Wing who led the effort to help sequence the genome of Asian rice from 1998 to 2005 that enabled the discovery of hundreds of agriculturally important genes, including genes for faster breeding and the ability for the plant to survive for up to two weeks underwater during periods of flooding.
In fact, Wing and his collaborators will celebrate the 10th anniversary of the completion of the Asian rice genome and the completion of the African rice genome at November’s 12th International Symposium on Rice Functional Genomics to be held in Tucson, Arizona.
Wing says that the results of the sequencing of the African rice genome means the emphasis now is on access to the yet untapped gene codes for traits that make African rice more resistant to long periods of drought and high salinity in the soils.
“A big focus of the rice community right now is what we call ‘green super rice,’” Wing told AFKInsider. “The ‘green’ means a rice that has less of an environmental footprint; it requires less water, less fertilizer, less pesticides and can grow in more marginal soils. The ‘super’ is higher yielding and more nutritious.”
Wing’s July research paper published online in Nature Genetics was co-authored by Judith Carney, a professor in the Department of Geography and the Institute of the Environment and Sustainability at UCLA.
Carney is also the author of the 2001 book Black Rice, which chronicles the history of rice cultivation along the rivers of West Africa and the role African rice played in the lucrative rice production in the Carolinas during the period of slavery.
The regional wealth created during that period, Carney writes in Black Rice, resulted from ”the large number of slaves imported directly from the rice area of West Africa who possessed knowledge of the crop’s cultivation.”
But rice, as a staple food crop in Africa, dates back further.
“By 1460 the Portuguese had completed reconnaissance of the Upper Guinea Coast, the densely populated region from Senegal to Liberia that would serve as a major focus for the Atlantic slave trade. Over the next centuries European mariners would call this region the Grain or Rice Coast after its specialized production of cereals,” notes Carney in the book.
Today, rice remains a staple food in Africa and cultivated primarily along the Upper Guinea Coast region from Senegal to Liberia.
“You find rice in flooded areas and you also have upland rice, which is more rain-fed rice,” Wing told AFKInsider. And then you have rice that grows in the mangroves, which is between the ocean and dry land.”
“The critical factor for rice production is sufficient rainfall to grow it or access to wetlands, such as coastal estuaries, river floodplains, inland swamps, UCLA’s Carney told AFKInsider.
Carney, who has hands-on experience with working with small, family rice farmers in West Africa, says rice cultivation can be labor-intensive for these farmers because “few people have access to machines” and do the work with basic agricultural tools like hoes.
“There are rudimentary milling machines, which eases the labor burden of removing hulls for a marketable product. But I am referring principally to family farms, not emerging trends of larger scale production evident in Mali by land leasing to other countries,” Carney told AFKInsider.
Despite the rudimentary tools of the family farms and seemingly limited growing conditions in sub-Saharan Africa, there is a concerted effort to increase rice production.
“Rice is very important. Rice is a food that really feeds the poor; it’s cheap, it has good calories and it’s definitely a staple in West Africa,” Dr. Wing told AFKInsider.
“Rice for the World”
With United Nations predictions that the world’s population will increase to more than 9 billion people – many who will be living in regions with scarce food access – by the year 2050, some feel a new African “super rice” may be part of the solution.
In fact, the upcoming Oct. 27-Nov. 1 International Rice Congress in Bangkok has the theme of “Rice for the World.”
That event is organized by the International Rice Research Institute which conducted training in the latest rice production technologies July 18 to August 15 in the Philippines for researchers from Benin, Burkina Faso, Congo, Cote d’ Ivoire, Kenya, Guinea, Mali, Tanzania, and Togo.
The Institute had previously done training for the other Coalition for African Rice Development member countries of Cameroon, Ghana, Guinea, Kenya, Madagascar, Mali, Mozambique, Nigeria, Senegal, Sierra Leone, Tanzania and Uganda in collaboration with – and funded by – the Japan International Cooperation Agency.
Another indication that rice may be on the verge of a major push in Africa came in April, when the organization AfricaRice announced in that its 2014-2020 Development Plan includes returning its headquarters to Côte d’Ivoire and establishing three Regional Centers: The West Africa Regional Center in Senegal; East and Southern Africa Regional Center in Tanzania; and a yet to be determined Central Africa Regional Center – each focusing on specific countries, including Madagascar, Uganda, Benin, Nigeria, Liberia and Sierra Leone.
But expanding rice cultivation in some of these sub-Sahara African countries to help feed an ever-growing population will be no small feat.
“They do grow rice in these areas,” Dr. Wing told AFKInsider. “It’s basically more of a transplant of rice from West Africa or Asia into these regions and they must have enough water to be able to support it.”
According to UCLA’s Carney, in response to the 2008 global rice crisis, and to concern with climate change and the global financial crisis, new forms of investment are underway to secure food production by leasing wetlands of sub-Saharan Africa.
“Rice cultivation is expanding on the wetlands of Mali through land leasing to foreign sovereign wealth funds and investment groups. Some similar projects are occurring in Sudan and the Tanzania coast, as well,” Carney told AFKInsider.
But there remain logistical issues to this expansion.
“Where there are roads and a market infrastructure, smallholder rice growers can make a living but this is often not the case,” Carney told AFKInsider. “There is an emphasis on rice self-sufficiency by growers, however, which buffers producers a bit from spikes in rice prices.”
“But then you have to store it, and there’s a lot of problems with storage of surplus crops all through Africa,” Wing told AFKInsider.
Despite these obstacles, the new strains of African super rice being developed could be a big plus in the battle against both hunger and poverty in some regions.
“Smallholder rice growers hold much promise for Africa, which has become a major importer of the grain. Especially in urban areas and even when countries are traditionally rice growing nations like the Gambia,” Carney told AFKInsider.