India-China team unlocks genetic secrets of pea; would aid in developing better varieties

Sequencing and comparing 118 varieties of wild and domesticated peas have yielded new genetic clues that would help plant breeders develop better quality chickpea and lentils – the two commonest legumes consumed in India.

New pea varieties with improved characteristics like drought and frost tolerance; bigger in size and resistance to diseases may be realised in near future, thanks to the pea genetic information that a team of Indian and Chinese scientists reported in Nature Genetics on Thursday.

In the last three years, India’s average pea productivity varied between 1.3-1.4 tonnes per hectare. “Out study provides gene information that will help enhance productivity to 1.5 to 2 tons per hectare and will deliver new varieties faster,” Rajeev Varshney, one of the corresponding authors from International Crop Research Institute for Semi-Arid Tropics, Hyderabad told DH.

Globally, the acreage of peas is ranked fourth among legumes, after soybeans, common beans and chickpeas. It is a source of protein, starch, fibre and minerals, and is endowed with a significant ecological sustainability advantage due to its nitrogen fixation capacity.

While plant scientists have unlocked many genetic secrets of the pea in the last decade, they realised that genetic mapping of a few individual lines would not be of much help to a breeder. Instead, a pan-genome of the pea is needed to create a genetic atlas that would help breeders pick up genes responsible for desirable traits.

The ICRISAT team participated in collaborative research involving ten Chinese institutes to create what the scientists said is a “high-quality reference genome and pan-genome” of the pea providing insights into the crop’s evolution and domestication, as well as valuable genomic resources for breeding research.

“We have mapped the genetic structure and variations of 118 cultivated and wild pea genotypes. Just as humans differ from one to another, the differences in plants are also encoded in their genetics. Our study details the genetic structure and variance of peas and how they evolved to this point in time. This data lays the groundwork for improving crops," said Varshney, currently associated with Murdoch University in Australia since February 2022.

“The new reference genome improves the knowledge of the genetics underlying the giant size of the pea genome and will facilitate future breeding studies that may help feed the world,” the team reported in the journal.

The study provided a deeper understanding of genes that could have a role in adaptation to climate change and might help in developing climate resilient crops, Varsney said. Genomic selection would facilitate a rapid combination of superior genes and accelerate the breeding cycle.