A wild bean`s genes may help a key crop thrive on a hotter Earth

by CIAT Comunicaciones | Jan 23, 2020

The climate change point-of-no-return may still be 1 degree C away. But that is of little solace to the people whose lives have already been upended by a warmer climate. They include growers and consumers of one of the most important protein sources in low-income countries: the common bean, a staple in diets from the highlands of Central America to the vast expanses of sub-Saharan Africa.

Through warming and unpredictable weather, bean fields are being abandoned or declining in productivity. In doing so, they are joining the growing list of climate casualties ranging from malnutrition and food insecurity to migrations and social unrest.

Already a staple crop for hundreds of millions of people in low-income countries, beans are now pointed to as an iron-rich replacement for meat in rich-world diets. If current dietary trends continue – and new ones catch on – the world is going to have to figure out how to produce a lot more beans on a warmer, hungrier planet.

Fortunately, scientists are working on a globe-spanning project to make the common bean more resistant to heat. The secret lies in its wild ancestor, the tepary bean, which has been grown for at least 2,500 years in the hot, arid regions of the Southwestern United States and Mexico. Researchers are working to exploit the genes responsible for climate robustness in tepary bean – known as Phaseolus acutifolius – and breed them into the common bean, or Phaseolus vulgaris.

“Low-fertility soils have been a problem for a long time but we didn’t address heat before,” said Celestina Xerinda, a bean breeder at the Mozambique Institute of Agricultural Research (IIAM), referring to her institution’s research priorities. “Under this project, we expect to develop a variety that is tolerant to heat stress because we are starting to get very high temperatures and the current genotypes (used by farmers in Mozambique) are not tolerant to heat.”

In Mozambique, a Southeast African nation with a population of about 30 million people, beans are the second most important source of protein for most people after meat, said Xerinda. Heat is exacerbating a “complex series of problems” facing the agricultural sector, she said, during a recent meeting of colleagues at the International Center for Tropical Agriculture (CIAT) (now part of the Alliance of Bioversity International and CIAT), as part of the Crop Trust-led Crop Wild Relative Project.

See: https://blog.ciat.cgiar.org/a-wild-beans-genes-may-help-a-key-crop-thrive-on-a-hotter-earth/

Figure:  Steve Beebe (R), the leader of CIAT’s bean program, guides colleagues from Central America and Africa through an experimental greenhouse at CIAT’s campus in Palmira, Colombia.