The pan-genome contains all possible genes of all chickpea species, including previously unidentified genes. Credit: Carl Davies/ CSIRO

An international research team has created a pan-genome by sequencing the genomes of cultivated and wild species of chickpeas1. The pan-genome contains all possible genes of all the plant’s species, including previously unidentified genes. These new genes help chickpeas to adapt to climate change, giving rise to climate-resilient varieties.

The researchers say this knowledge will speed up the breeding of chickpea varieties with enhanced yield, and greater resistance to drought, heat and disease.

The team, which included scientists at the International Crops Research Institute for the Semi-Arid Tropics in Hyderabad, India, developed a detailed genetic variation map from 3,171 cultivated and 195 wild species of chickpea.

The researchers, led by Rajeev K Varshney, identified more than 29,000 genes. Of these, 1,582 were new genes that help chickpeas respond to oxidative stress, acidic environment and cold. They also detected genes that impair crop performance. Removing these genes could improve crop yield and quality.

Analysis revealed that chickpeas, after originating in the Fertile Crescent, migrated across the globe following two routes – one to South Asia and East Africa, and the other to the Meditarranean region plus the Black Sea and Central Asia.

Sequencing the genomes also revealed that the chickpea population shrank considerably about 10,000 years ago, reaching its minimum size around 1,000 years ago. “However, the plant’s population has expanded in the last 400 years, suggesting a strong contribution of chickpea agriculture around the world,” says Varshney.