IRRI reveals scientific breakthrough for low and ultra-low glycaemic index rice

MANILA, PHILIPPINES (16 October 2023) – In an effort to help curb the rising cases of diabetes globally, scientists from the International Rice Research Institute (IRRI), a CGIAR Research Center, have identified the genes responsible for low and ultra-low glycaemic index (GI) in rice. This new discovery will be able to convert popular rice varieties into low and ultra-low GI for refined white rice, through conventional breeding methods, keeping high-quality grain and without compromising yield.

The first batch of ultra-low GI rice samples, developed from the Samba Mahsuri x IR36ae, was formally presented to Philippine President Ferdinand Marcos, Jr. at the opening ceremony of the 6th International Rice Congress. IRRI has previously identified two low GI Philippine varieties, IRRI 147 and IRRI 125, that were already released in the Philippines as salt-tolerant varieties. Based on clinical validation on human volunteers in a cohort study, IRRI 147 depicted a GI value of 55 and IRRI 125 had a GI value of 51.1.

Diabetes is growing globally at an epidemic rate. According to the International Diabetes Federation, there were 537 million people with diabetes in 2021 and this is expected to increase 47% by 2047. Many cultivated rice varieties have a GI ranging from 70 to 92, which is not considered healthy for people with diabetes.

IRRI classifies GI levels below 45 as Ultra-low, 46-55 as low GI, 56-69 as intermediate GI, and high GI at 70 and above. The newly discovered ultra-low GI line has a GI level of 44, with translucent backgrounds.

In 2019, IRRI found highly significant marker-trait association markers for distinguishing intermediate versus high GI. The breakthrough comes in IRRI having now defined the genetics for low GI and Ultra-low GI and developed pre-breeding lines in a…