NEW YORK, May 2 (UPI) -- Genome researchers tracking the evolutionary history of rice say domesticated rice may have appeared as far back as around 9,000 years ago in China.
Previous studies had suggested domesticated rice may have had two points of origin, India and China, but genetic evidence points to China as the older source of the crop species, a release from New York University said Monday.
The study supports archaeological evidence gathered in the last decade pointing to rice domestication in the Yangtze Valley beginning approximately 8,000 to 9,000 years ago, while domestication of rice in the India's Ganges region began around about 4,000 years ago.
The researchers examined the history of domesticated rice by re-sequencing 630 gene fragments on selected chromosomes from a diverse set of wild and domesticated rice varieties.
Their results showed that the gene sequence data was consistent with a single origin of rice.
"As rice was brought in from China to India by traders and migrant farmers, it likely hybridized extensively with local wild rice," NYU biologist Michael Purugganan, one of the study's co-authors, said. "So domesticated rice that we may have once thought originated in India actually has its beginnings in China."
Asian rice, Oryza sativa, is one of world's oldest crop species.
