From Red to White: The Story of Today's White Rice

It all began with wild red rice, a single gene, and two mutations. Now white rice is the staple food of more than half of today's world's population. Ancient farmers found that the white-grained rice that interspersed with their red rice cooked faster (requiring less fuel), had hulls that were easier to remove, and a color that made disease and insects easier to see. Thus began the epic diaspora of white rice varieties from the Himalayan region to the rest of the world.

Researchers at Cornell University and elsewhere have found that 97.9 percent of all white rice is derived from a mutation (a deletion of DNA) in a single gene originating in the Japonica subspecies of rice; a mutation that is also found in the Indica subspecies of white rice. A second independent mutation (a single DNA substitution) occurred in the same gene in several Aus varieties of rice in Bangladesh, accounting for the remaining 2.1 percent of white rice varieties. Neither of these two mutations is found in any wild red rice species.  

Scientists are now studying how to introduce favorable genes from wild red rices into elite white cultivars to improve yields and provide better responses to stress. In the future, breeders can have red-grained rice without the undesirable weedy traits of wild red rice.

Read the complete article at http://www.news.cornell.edu/stories/Aug07/WhiteRice.kr.html.