Cotonou, Benin — A team of researchers from the Africa Rice Center (WARDA) and the national programs—led by Dr Moussa Sié, WARDA Lowland Rice Breeder, and Dr Kouamé Miézan, Irrigated Rice Breeder—has successfully used the NERICA technology to develop a new plant type adapted to African lowlands with good resistance to local stresses, yield potential of 6-7 t per ha, growth duration of 120 days and acceptable plant height.
The NERICA technology refers to the successful crossing by WARDA researchers of the two species of cultivated rice—Oryza glaberrima (African rice) and Oryza sativa (Asian rice)—to produce fertile plants that combine the best traits of both parents: high yields from the Asian parent and the ability to thrive in harsh environments from the African parent. The NERICA name was trademarked by WARDA in 2004.
“Given the high potential of the lowlands in Africa, the new breakthrough is expected to make an even bigger impact than the upland NERICA varieties,” stated WARDA Director General Dr Kanayo F. Nwanze.
About 60 varieties of the new plant type have been selected by farmers through the participatory varietal selection (PVS) process in several African countries—an approach that was successfully used in accelerating the dissemination of the upland NERICAs. “In early 2005, four Lowland NERICAs were released in Burkina Faso and two in Mali,” said Dr Sié.
The WARDA Varietal Nomination Committee recently named the 60 Lowland NERICAs in close consultation with the national agricultural research systems (NARS). The WARDA Board, Management and researchers gratefully acknowledged the scientific contribution of the NARS partners who have played a central role in the development of the Lowland NERICAs through the WARDA/CORAF ROCARIZ rice network.
For creating the Lowland NERICA, the scientists focused on crossing specific varieties of the African rice that were known for their resistance to some of the major lowland stresses with popular—but susceptible—Asian rice varieties.
The Asian rice O. sativa has two main strains, japonica (traditional rainfed or ‘upland’ rice) and indica (traditional irrigated or ‘lowland’ rice). In the creation of upland NERICA, japonica varieties were used in the crosses, while for developing the Lowland NERICA, the indica varieties were used.
In the same way as for upland NERICA, developing the Lowland NERICA posed a formidable scientific challenge because often attempts to cross the two rice species do not lead to reliable variety development. “We overcame the sterility blockage by backcrossing (crossing the hybrid to O. sativa to restore fertility),” explained Dr Sié.
“We are delighted that our prophetic vision is coming true and another amazing breakthrough has been achieved, thanks to the initiative taken by our scientists and the valuable contribution of the national programs,” Dr Nwanze commented. “The lowlands are indeed the most promising environments for rice expansion in Africa and the Lowland NERICAs, within a sustainable and diversified land use systems approach, has a high potential for transforming the prospects for food security in the region.”