Oryza sativa, having the common name Asian cultivated rice, is the much more common of the two rice species cultivated as a cereal, the other species being O. glaberrima, African rice. It was first domesticated in the Yangtze River basin in China 13,500 to 8,200 years ago.
Oryza sativa belongs to the genus Oryza and the BOP clade in the grass family Poaceae. With a genome consisting of 430 Mbp across 12 chromosomes, it is renowned for being easy to genetically modify and is a model organism for the study of the biology of cereals and monocots.
Description
Oryza rufipogon is the scientific name for brownbeard rice. This wild rice was first domesticated into Oryza sativa, and its subsequent divergence into japonica and indica subspecies, occurred through a long process of domestication, artificial selection, and hybridization. Domestication led to artificial selection of rice with a mutation that made seeds non-shattering. This forced grains to stay attached and made harvesting easier. The plant was also bred for vertical architecture in its growth to maximize field density, and the awns were selectively bred away to reduce bulk density. Oryza sativa then led to the creation of two subspecies, japonica and indica. Oryza sativa subsp. japonica was primarily grown in temperate and subtropical regions, the plant was shorter than indica and had darker leaves. Japonica grains are short, round, and plump, and have lower amylose content than indica. Oryza sativa subsp. indica was primarily grown in tropical and humid regions. Indica has a taller growth and lighter leaf color. The grains are thinner, longer, and have higher amylose content. Diagram Legend 1.a - wild rice (Oryza rufipogon) 1.b - grains of wild rice (Oryza rufipogon) 2.a - Japanese rice (Oryza sativa subsp. japonica) 2.b - grains of Japanese rice (Oryza sativa subsp. japonica) 3.a - Indian rice (Oryza sativa subsp. indica) 3.b - grains of Indian rice (Oryza sativa subsp. indica)
