The Nigerian Biosafety Management Agency (NBMA) has approved the commercial release of genetically modified, pest-resistant cowpea to farmers in Nigeria.
This places the country on the path to becoming the first country ever to cultivate biotech cowpea. This development adds a new crop to the global biotech basket from Africa.
NBMA’s approval allows the Institute for Agricultural Research (IAR) to commercially release Pod Borer-Resistant Cowpea (PBR Cowpea)-event AAT709A, genetically improved to resist Maruca vitrata. This permit is valid until the end of 2022.
Principal Scientist in Plant Biotechnology at International Institute of Tropical Agriculture (IITA), Leena Tripathi, expressed delight stating, “This is indeed good news for IITA and Nigeria at large, as the first GM food crop will be available for commercialisation.”
Cowpea is an important staple crop in sub-Saharan Africa, serving human consumption needs as well as being a good source of quality fodder for livestock. However, cowpea farmers face a challenge with a traditionally low yield factor due to its susceptibility to many insect pests at different stages of its production lifecycle. As a result, if farmers want to get a good yield they need to apply multiple insecticide sprays during the course of the production in the fields.
One of the most damaging insect pests that attack the cowpea plant is the Maruca vitrata, commonly called the maruca pod borer, which causes 70–90 per cent yield loss for farmers. Due to high costs and, sometimes, unavailability of suitable insecticides, many cowpea farmers resort to harmful cotton insecticides to spray cowpea fields. This has unfortunately led to significant numbers of intoxication and deaths.
IITA, which has cowpea as one of its mandate crops, along with other research partners, decided to focus on developing an improved cowpea variety that would be resistant to maruca. To achieve this, more than 15,000 cowpea varieties in the IITA germplasm bank were evaluated for resistance to maruca.
Giving an overview of the project, IITA Legume Geneticist and Breeder, Christian Fatokun stated that the researchers also evaluated wild relatives where resistance to this pest was detected in one called Vigna vexillata. Concerted efforts were made to cross this wild relative to cowpea but proved unsuccessful.
With the lack of success of conventional breeding for resistance, the collaborators on the project decided to adopt a biotech approach that would result in genetically modified cowpea.
Previous research using a bacterium called Baccilus thuringiensis (Bt) to confer resistance in maize crop had proved quite successful and some of the Bt gene strains have been found be effective against maruca.
With genes provided by Monsanto and initial phases of product development conducted at the Commonwealth Scientific and Industrial Research Organisations (CSIRO) in Australia, significant milestones were achieved in developing cowpea lines expressing the Bt (Cry1Ab) gene that confers resistance to maruca pests.