An international team of researchers has fully sequenced the genome of a climate resilient bean that could bolster food security in drought-prone regions.
The sequencing of the hyacinth bean or 'lablab bean' [Lablab purpureus] paves the way for wider cultivation of the crop, bringing nutritional and economic benefits, as well as much needed diversity to the global food system.
"The first green revolution was achieved with major crops like wheat and rice. Orphan crops like lablab could pave the way for the next green revolution," said Oluwaseyi Shorinola, one of the lead authors of the research from the Kenya-based International Livestock Research Institute (ILRI) and a visiting scientist at the John Innes Centre.
The legume, native to Africa, is cultivated throughout the tropics and produces highly nutritious beans which are used for food and livestock feed. Its extreme drought-resilience and ability to fix nitrogen means that it thrives in a range of environments and conditions.
In this research the team identified the genomic location of important agronomic traits of yield and seed/plant size, and they documented the organisation of genes which inhibit a key enzyme in the digestion process in humans.
They also tracked the history of lablab's domestication, confirming that this occurred in paralell in two different places.
Mark Chapman, a lead Mark Chapman, another lead author of the study and Associate Professor at the University of Southampton, said: "This is an exciting finding, and it opens the door to studying whether agronomic traits can evolve more than once using the same genes, or if different pathways can evolve to give the same outcome. This information offers a valuable resource for genetic improvement."
The full genome sequence plus the identification of key genes provides opportunities for targeted breeding to reduce these antinutritional properties.
The plant's adaptability suggests high genetic diversity, which means it's possible to select different adaptive varieties for different environments and climatic challenges.
African-led research
The research process itself was ground-breaking for its leadership by African scientists.
Meki Shehabu, co-author of the study and a scientist at ILRI in Ethiopia, said. "What makes this project special is that it is led by African scientists, in collaboration with scientists from international institutes."
To make this happen, the project had to overcome constraints such as Africa's relative lack of sequencing facilities and high-performance computing infrastructure, as well as the bioinformatics capacity required. The researchers addressed these challenges by using new low-cost portable sequencing platforms, carrying out in-depth capacity building (including an Africa-based eight-month residential bioinformatics training), and working carefully to facilitate equitable international collaboration.
Looking forward, the team anticipates that the genomic resource will inspire genetic improvement work on lablab - and other under-utilised indigenous crops - with the aim of increasing food and feed availability on the African continent and beyond.
Chromosome-level genome assembly and population genomic resource to accelerate orphan crop lablab breeding is available in Nature Communications.
How orphan crops such as the lablab bean can help diversify the global food system
The lablab bean is one of a long list of 'orphan crops': indigenous species that play an important role in local nutrition and livelihoods, but that receive little attention from breeders and researchers.
The three major crops that currently provide over 40 percent of global calorie intake - wheat, rice, and corn - receive the bulk of breeding and crop improvement efforts. With so little diversity in crop cultivation, the global food system is vulnerable to environmental and social instabilities. Underutilised crops like lablab hold the key to diversified and climate-resilient food systems and genome-assisted breeding is one promising strategy to improve their productivity and adoption.
"When it comes to valuing a crop, people often focus on its global market value in US dollars," said Chris Jones, Program Leader for Feed and Forage Development at the (ILRI) based in Kenya, and one of the lead authors of the study. "However, for farmers who struggle to produce enough food, the value of a crop like lablab is incredibly high. Although it may be cultivated on a smaller scale compared to major crops, its impact on food security can be significant, and we need to recognize that."
