BOTANY

Detailed explanation-1: -Recent genetic research suggests that domesticated rice (O. sativa ssp. japonica) first occurred in southern China, including the Yangtze River valley and the Pearl River Basin.

Detailed explanation-2: -The lower stretches of the Yangtze River valley in eastern China had long laid claim to early domestication, based on the discovery of roughly 8, 000-year-old grains in archaeological sites there.

Detailed explanation-3: -Rice is believed to have been domesticated ∼9, 000 y ago, although debate on its origin remains contentious. A single-origin model suggests that two main subspecies of Asian rice, indica and japonica, were domesticated from the wild rice O. rufipogon.

Detailed explanation-4: -The Yangtze basin contributes nearly half of China’s crop production, including more than two-thirds of the total volume of rice. Among the other crops grown are cotton, wheat, barley, corn (maize), beans, and hemp.

Detailed explanation-5: -Global Rice Production and Consumption Globally, the top rice-producing country is China, followed by India.