Chickpea population sequencing

On April 29, 2019, "Nature Genetics" was published online by the China National Gene Bank, ICRISAT, and BGI-research. A research paper entitled "Resequencing of 429 chickpea accessions from 45 countries provides insights into genome diversity, domestication and agronomic traits" was completed by a team of scientists from 21 research institutions around the world. The study completed genome sequencing of 429 chickpea lines from 45 countries and re-sequenced 15,000 chickpeas, covering 82.7% of the global chickpea germplasm resources. Completed the largest chickpea genome resequencing study ever. The research results have clearly identified the functional genes for drought tolerance and heat resistance of this species, providing valuable genetic resources for the cultivation of high-yield and stress-resistant chickpeas.

It has important practical significance for the development of arid and semi-arid areas

Chickpea is a herbaceous plant belonging to the legume butterfly family. Its main characteristics are developed root system and strong drought tolerance. At the same time, the nodule has strong nitrogen fixation ability. It is one of the main foods in India and Pakistan. Extensive planting. Because chickpeas are extremely drought-tolerant, the results of this whole-genome resequencing of chickpeas have important practical significance for the development of my country's northwest, southwest and other vast arid and semi-arid regions.

The research mainly maps the origin and spread history of chickpeas in India and Africa, and provides key insights into the genetic diversity of chickpeas and their domestication and agronomic traits. For agricultural production, this means that new varieties of chickpea can be cultivated with high yield, disease resistance and stress resistance, which can better adapt to the unpredictable climate and adapt to a wider range of climatic conditions.

Study covers 429 chickpea strains in 45 countries

The chickpea materials selected in this study represent 78% of the genetic diversity of varieties collected from all over the world, and 4.97 million specific SNP loci were identified from them, exceeding previous population studies on chickpeas. Through principal component, systematic evolution and population structure analysis, 429 genetic materials were divided into wild species, landraces and cultivated species. By comparing different populations, it is found that chickpeas have lost nearly 80% of their genetic diversity in the history of domestication, suggesting that human ancestors played a huge role in the history of domestication. This also shows that the use of wild relatives for genetic breeding has great potential.

More than 90% of the world's chickpea growing areas are located in South Asia. It is said that drought and rising temperatures have caused a global loss of more than 70% of chickpea production. Due to rising temperatures, chickpeas as a cold-loving crop may further reduce productivity. "Genome-wide association studies have identified 13 candidate genes for agronomic traits. For example, we can identify genes (such as REN1, β-1,3-glucanase, REF6) that can help crops tolerate temperatures up to 38°C. Temperature and provide higher productivity,” said Dr. Rajeev Varshney, Director of the Genetic Resources Program of the ICRISAT.

The study also confirmed that chickpeas are fertile crescent land (a series of fertile lands in the Mesopotamia and nearby areas of West Asia and North Africa) and the Mediterranean region, which was transported to India via Afghanistan, and may be brought back to the original after 200 years. Place of origin. This new study speculates that chickpeas may have been introduced into the New World directly from Central Asia or East Africa instead of the Mediterranean. "Our research shows that the fertile crescent and the Mediterranean are the main centers of possible origin of chickpeas, and Ethiopia is the secondary center of diversity. The migration route of chickpeas from the Mediterranean/fertile crescent to Central Asia may be the same as that of East Africa. The migration route (Ethiopia) and South Asia (India) to Central Asia are parallel.” Dr. Rajeev Varshney added.