‘Wild’ genes open up opportunities for healthier, climate-smart rice

Date:01-31-2018

The wild relatives of rice are repositories of important traits that help breeders improve rice. (Photo: IRRI)

The genome sequencing of seven wild rice varieties has finally been completed. This breakthrough is expected to provide opportunities for breeders worldwide in developing better rice varieties that will respond to the changing needs of the farmers and the consumers.

This discovery is outlined in the article Genomes of 13 domesticated and wild rice relatives highlight genetic conservation, turnover and innovation across the genus Oryza published by Nature Genetics. The study details the generation of seven wild and two cultivated genomes (IR8 and N22). The IR8, popularly known as “miracle rice,” was developed by rice scientists from the International Rice Research Institute (IRRI). IR8 was one of the rice varieties that ushered in the Green Revolution in Asia during the 1960s and prevented worldwide starvation and famine.

“As the global population is projected to increase by almost 3 billion by 2050, rice breeders urgently need to develop new and sustainable rice varieties with higher yield, healthier grains and reduced environmental footprints. The completed sequencing of the seven wild rice varieties is a significant progress to drive further genome evolution and domestication,” explained Dr. Rod Wing, leader of the International Oryza Map Alignment Project (IOMAP), an AXA Chair holder at the International Rice Research Institute, Professor at the University of Arizona, and one of the lead scientists in the study.

“Because the wild relatives of rice are adapted to different biogeographic ranges and can tolerate many biotic and abiotic stresses, they continue to be an important reservoir for crop improvement. Strategies to harness such traits show clear promise to meet the future consumption demand,” he further explained.

Dr. Ruaraidh Hamilton, IRRI lead scientist for genetic diversity and head of IRRI Genebank welcomes this breakthrough. “This opens the doors for rice breeders to harness genes from the wild relatives of rice, allowing us to improve crops with traits that are preferred by farmers and consumers. It will also bring us steps closer to our goal of ensuring global food and nutrition security through sustainable rice production,” he said.

The cultivation of rice, the staple food of more than half of the world’s population, faces challenges including the threat of climate change and the onslaught of pests and diseases. The genetic traits that allow crops to overcome most, if not all, of these stresses can frequently be found in the wild relatives of rice. This research could significantly improve the rice breeding scenario, allowing shorter periods for genetic discovery and varietal improvements that would normally take years to develop.

This scientific breakthrough was a product of close collaborative research work with multiple institutes across the globe throughout the years. It all started in 2003 when Dr. Wing and Dr. Scott Jackson, a professor, GRE Eminent Scholar, and Director of the Center for Applied Genetic Technologies at the University of Georgia, initiated a collaboration with Dr. Darshan Brar, former IRRI plant breeder and Head of the Plant Breeding and Genetics Division during a visit to IRRI headquarters in Los Baños, Philippines. Having isolated DNA for a number of wild species, Drs. Wing and Jackson took the samples back to their laboratories to produce the genome libraries used for sequencing.