African-led genome assembly of lablab bean marks step forward in diversifying global food supply

By Nicholas Karavolias

July 15, 2022

African scientists can take the lead in making genetic improvements to neglected native plants that can help diversify the world’s food supply, a new study suggests.

Most of the food we eat is sourced from a miniscule fraction of total plant diversity. Just three major crops currently provide more than 40 percent of global calorie intake. Breeding and crop improvement efforts are often restricted to those few crops, further reinforcing the trend of poor agricultural biodiversity and making global food systems vulnerable to environmental and social instabilities.

But that limited approach may be changing, now that an African-led international team of researchers has completed the first plant genome assembly produced in Africa. Historically, crops indigenous to Africa have been sequenced outside of the continent, and in many cases did not involve African scientists.

In this study, researchers worked with lablab, a legume native to the continent that is cultivated for food and feed in the tropics. It is also rich in bioactive compounds with pharmacological potential, including against SARS-Cov2, the researchers noted.

Besides reflecting an incredible technological feat, the study — published in a pre-print — also developed a precedent for African scientists to lead on genome assemblies and other research endeavors, especially when crops native to Africa are concerned.

“Our approach provides a valuable resource for lablab improvement and also presents a model that could be explored by other researchers sequencing indigenous crops, particularly from low- and middle-income countries,” the authors wrote.

The research — led by scientists at the International Livestock Research Institute in collaboration with the John Innes Center and several European universities — comes at a time when yield improvements of major crops like wheat, maize, and rice have plateaued.

Meanwhile, native crops that are resilient to climate change, nutrient-rich and locally important offer bountiful potential, but remain largely understudied. These plants, often referred to as orphan crops due to their general neglect by researchers, provide an incredible opportunity to diversify the food supply in a culturally appropriate way.

Farmers and scientists alike recognize the value of focusing new efforts on improving and integrating orphan crops into production to reap the positive benefits that come with diversifying the agricultural landscape.

The assembly of the lablab genome provides a rich basis for future crop improvements, while the mechanism by which it was produced has shifted the paradigm for how genomic resources are generated.

“Genome-assisted breeding offers hope of a new green revolution by helping to uncover and unlock novel genetic variation for crop improvement,” the authors wrote. “Over the last 20 years, the genomes of 135 domesticated crops have been sequenced and assembled, including those of orphan crops. However, it has recently been acknowledged that researchers from Africa are grossly underrepresented in the genome sequencing efforts of their indigenous orphan crops.”

Making use of international collaborations to complement the expertise of African scientific leaders has proven to be a functional model for future crop improvement. By generating genomic resources for orphan crops like lablab, huge improvements can be attained more rapidly than ever before.

Improvements of other orphan crops, such as teff, millet, yam and cassava, can provide important pathways for future food security and climate resilience, especially when research initiatives are led by those most intimately linked with the cultivation of these crops.

Image: Lablab bean (lablab purpureus) has both food and pharmacological value. Photo: Shutterstock/guloabang