The Africa Rice Center (AfricaRice) has launched a 5-year project to rapidly identify and harness high-value genes from Oryza glaberrima – known commonly as the African rice as it is a cultivated species that is found only in Africa – for developing new rice varieties that can cope with the increasing challenges of drought, flooding and soil-related constraints such as iron toxicity in the continent.
The project “Rapid mobilization of alleles for rice cultivar improvement in sub-Saharan Africa” will be implemented by AfricaRice in partnership with the National Institute of Agrobiological Sciences (NIAS), Japan; Cornell University, USA; the International Rice Research Institute (IRRI), Philippines; and the National Cereals Research Institute (NCRI), Nigeria. The project is supported by the Bill & Melinda Gates Foundation.
“The new initiative complements the ongoing research on stress-tolerant rice that is being carried out by the Center with several partners,” said Dr Marco Wopereis, AfricaRice Deputy Director General.
Rice farmers in sub-Saharan Africa (SSA) face many environmental constraints. Drought is particularly devastating to Africa’s rice production since almost 70% of the region’s rice area is rainfed. Thus about 7 million ha of rice area in SSA is potentially drought-prone. Iron toxicity is a serious constraint in lowland rice ecologies, which represent about 53% of the total rice area in SSA.
Flooding affects as much as one-third of the rainfed lowland areas of SSA, when there is heavy rain and blocked drainage. Most lowland rice farmers in Africa practice direct-seeding, making them vulnerable to total crop loss if flooding occurs during seed germination. In such situations, tolerance to flooding during germination known as ‘anaerobic germination ability’ in rice seeds is needed to overcome the stress.
“Drought tolerance, iron tolerance and anaerobic germination ability are therefore among the key traits for rice breeding in Africa,” said Dr Venuprasad Ramaiah, AfricaRice lowland rice breeder and coordinator of the project. “Rapid development and dissemination of rice varieties with these traits are crucial to stabilize and increase rice production in Africa.”
Currently, rice breeding programs are mainly sourcing genes of stress tolerance from Oryza sativa (known commonly as the Asian rice). Research at AfricaRice has shown that the African rice is a rich repository of genetic material that can provide tolerance to several stresses, particularly drought, iron toxicity and flooding during germination.
In this project, the main focus will be on using the African rice as a donor of stress tolerance. The project will make use of AfricaRice’s collection of more than 2,000 samples of seed of this native African rice species.
As a first step, the project will identify genes/gene-based markers related to iron tolerance, drought tolerance and anaerobic germination ability. The genes will then be incorporated using marker-assisted backcrossing (MAB) into commercially valuable rice varieties without losing useful characteristics which make them popular with farmers.
“The new resilient varieties are expected to directly enhance yield levels and reduce risk in farmers’ fields. In addition, varieties with anaerobic germination capacity will enable direct seeding in flood-prone areas, greatly reducing labor needs for transplanting and weeding, which are often provided by women in SSA,” said Dr Ramaiah.
Representatives of the partner organizations participated in the project launch meeting that was held, 10-12 April 2014, at the AfricaRice Research Station in Ibadan, Nigeria, to discuss and confirm the objectives and deliverables of the project.
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