India-led team decodes genome sequence of the chickpea

A global research project led by a Hyderabad institute claims to have sequenced 90 genomes of the chickpea, paving the way for improved grain yields, greater drought tolerance and enhanced genetic diversity.

Researchers at the International Crops Research Institute for the Semi-arid Tropics (Icrisat) heralded their findings as a “scientific breakthrough” and published the results in the journal Nature Biotechnology.

The paper provides a map of the structure and functions of the of the genes that define the chickpea plant. It also reveals clues on how the sequence can be useful to crop improvement for sustainable and resilient food production toward improved livelihoods of smallholder farmers particularly in marginal environments of Asia and sub-Saharan Africa.

The milestone came as the result of years of genome analysis by the International Chickpea Genome Sequencing Consortium (ICGSC), led by Icrisat and involving 49 scientists from 23 organisations in 10 countries. 

Genetic markers

The researchers succeeded in identifying an estimated 28,269 genes of chickpea after sequencing CDC Frontier, a large-seeded, or kabuli, chickpea variety. Re-sequencing of an additional 90 genotypes provided millions of genetic markers and low diversity genome regions that may be used in the development of superior varieties with enhanced drought tolerance and disease resistance. 

This will help chickpea farmers become more resilient to emerging challenges brought about by the threat of climate change. The genome map can also be used to harness genetic diversity by broadening the genetic base of cultivated chickpea genepool.

Chickpea is the second largest cultivated grain food legume in the world, grown in around 11.5m hectares mostly by resource-poor farmers in the semi-arid tropics. The highly nutritious, drought-tolerant chickpea is crucial to the food security in India, which is the largest producer, consumer and importer of the crop. 

Icrisat and its partners have once again demonstrated the power of productive partnerships by achieving this breakthrough in legume genomics,” said Dr William Dar, director general of the institute. “Genome sequencing will play a crucial role in speeding up the development of improved varieties for smallholder farmer crops such as chickpea.”

Dr Rajeev Varshney, a director of Icrisat, added: “Genetic diversity, an important prerequisite for crop improvement, is very limited and has been a serious constraint for chickpea improvement. This study will provide not only access to ‘good genes’ to speed up breeding, but also to genomic regions that will bring genetic diversity back from landraces or wild species to breeding lines.

At the moment, it takes four to eight years to breed a new chickpea variety. This genome sequence could reduce to half the time to breed for a new variety with market-preferred traits.”

Political mileage

Indian politicians have increasingly aligned themselves with the research and have been quick to point out how the research will help accelerate crop growth through marker-assisted breeding.

Ashish Bahuguna, India’s agriculture secretary, said: “Decoding of the chickpea genome will facilitate the development of improved varieties with higher yields and greater tolerance to biotic and abiotic stresses. This will help chickpea farmers to increase productivity, reduce cost of input and realise higher incomes.

The chickpea has now become the second food legume genome sequenced in India after pigeon pea.