Cowpeas Are Helping Us Prepare for a Hotter, Drier Future
(Ensia) Imagine spending three weeks outside without water while temperatures regularly rise above 40 °C (104 °F). That’s a recipe for disaster for humans — and for most plants, too. But to many varieties of cowpea, it’s a mere hiccup on the way to producing high-protein, nutritious beans that have cultural significance around the world.
Ousmane Boukar, a cowpea breeder at the International Institute of Tropical Agriculture in Nigeria, is working to understand how cowpeas withstand such brutal droughts. That’s important because regions of West Africa, where Boukar says that most people eat cowpea practically every day, are expected to get drier and hotter with climate change. For food security and economic stability, growers will need varieties that can withstand those changes.
Along with other scientists, Boukar is using emerging information about cowpea genetics to better understand how the crop responds to drought — and how we might make it even more tolerant. While cowpeas have a reputation for tolerating drought, individual varieties differ greatly. If researchers find that varieties that thrive under dry conditions all have the same mutation in one gene, they can investigate that gene to learn how — or if — it affects drought tolerance, then breed it into other varieties to make them more tolerant, too.
…(Ira Hernitera, Ph.D. student at the University of California, Riverside) recently helped sequence the cowpea genome, making it easier for researchers to determine the genetic underpinnings of specific traits, including drought tolerance. For instance, Boukar’s team screened over 1,000 cowpea lines to identify those with the highest drought tolerance. They selected the 10 varieties that performed best for further breeding. The genome sequence of cowpea could make it easier for Boukar’s team to figure out which genes — or combinations of genes — in those 10 varieties contribute to drought tolerance, helping breeders maximize the number of genes for drought tolerance in new varieties.
Herniter says that because less research has been done on cowpeas than on crops like rice and soybean, “many of the large leaps” in breeding have not yet been taken. That means potentially more bang for the research buck in terms of advancing crop productivity and food security.
International Institute of Tropical Agriculture researcher Ousmane Boukar (left) and a colleague screen cowpeas for drought resistance.
Photo courtesy of Ousmane Boukar