The grain that feeds half the world may have taken a big leap forward.
Scientists report the biggest improvements in rice productivity in decades.
If the results hold up in further tests, it could greatly increase harvests of a critical staple crop at a time when global population growing rapidly.
Researchers found one version of a gene that increased the number of branches in the flowering part of the plant. Each plant produced more rice as a result.
They used conventional breeding to introduce this gene version into five rice varieties. These varieties produced from 28 to 85 percent more rice than the parent strains, according to a new study in the journal Nature Scientific Reports.
That's an "eye-popping" yield increase, said University of Arkansas rice breeder Xueyan Sha, who was not involved with this research. Normally, he added, "if we can achieve 6 percent, we can probably consider it a great achievement."
Rice yields have not improved much since the 1960s "Green Revolution." That's when breeders found a gene that made plants shorter and less likely to fall over and therefore able to hold more rice grains. Farmers called the new variety "miracle rice" for its dramatic yield gains.
Experts say big increases in food production will be needed to feed the additional two billion or so people expected on the planet by 2050.
The new research was a small-scale, controlled experiment, Sha noted, and it's not clear how the results will hold up in farmers' fields. But he said he's "cautiously optimistic."
Not all rice varieties the scientists tested saw the same hefty productivity increases. That's another reason for caution, according to rice geneticist Shannon Pinson with the U.S. Department of Agriculture.
"There's something exciting here," she said. "I don't think it's as exciting as Green-Revolution caliber."
Study authors say their new rice varieties should be available to farmers in two to four years.