Previously it was believed that agriculture began in West Asia in a region known as the Fertile Crescent with the domestication of barley and wheat. Later a new Fertile Crescent was discovered in China where rice cultivation began much before agriculture in West Asia. Archaeology in Lahura-Deva site in Uttar Pradesh had recently found carbonised material containing grains of cultivated rice along with wild grass and it was considered to be proof that rice cultivation started in India much before in China.
Now according to American and Taiwanese researchers rice domestication happened in multiple sites, independently
While there is consensus that rice had its roots in Asia, whether it was domesticated in southern China alone or at multiple locations has been under debate.
In a bid to trace the ancestral roots of rice — a cereal eaten by more than half of the world’s population — plant geneticist Barbara Schaal at Washington University and her colleagues analysed the genetic make-up of wild and cultivated rice varieties.
Their studies show that the indica variety was domesticated south of the Himalayas within a region spanning eastern India, Myanmar and Thailand, while the japonica variety was domesticated from wild rice in southern China.
“We now have strong evidence for multiple sites of domestication of rice,” Schaal told The Telegraph over the telephone.
The new studies also suggest that an additional — third — domestication event might have occurred in India, giving rise to a minor variety of rice called “aus” — a drought-tolerant strain cultivated in India and Bangladesh.
The two major rice varieties grown worldwide today — Oryza sativa indica and Oryza sativa japonica — owe their origins to two independent events of domestication thousands of years ago, American and Taiwanese researchers said. [Rice roots lie in east India]