Oryza rufipogon is a species of flowering plant in the family Poaceae. It is known as brownbeard rice, wild rice, and red rice. In 1965, Oryza nivara was separated off from O. rufipogon. The separation has been questioned, and now many sources consider O. nivara to be a synonym of O. rufipogon. O. nivara may be treated as the annual form of O. rufipogon.
It is native to East-, Southeast- and South- Asia. It has a close evolutionary relation to Oryza sativa, the plant grown as a major rice food crop throughout the world. Oryza nivara is a possible wild progenitor of cultivated rice. Both have an AA genome.
Description
For those who accept Oryza nivara as a separate species, it is an annual, short to intermediate height (usually <2 metres (6 ft 7 in)) grass; panicles usually compact, rarely open; spikelets large, 6–10.4 millimetres (0.24–0.41 in) long and 1.9–3.4 millimetres (0.075–0.134 in) wide, with strong awn (4–10 centimetres (1.6–3.9 in) long); anthers 1.5–3 millimetres (0.059–0.118 in) long. It grows in shallow water up to 0.3 metres (1 ft 0 in), in seasonally dry and open habitats. It is found growing in swampy areas, at edge of pond and tanks, beside streams, in ditches, in or around rice fields.
Genetics
As with a great many plants and animals, O. rufipogon has a positive correlation between effective population size and magnitude of selection pressure. O. r. having an EPS of ≈140,000, it clusters with others of about the same EPS, and has 78% of its amino acid sites under selection.
In India, the Pallikaranai marshland contains the wild rice O. rufipogon, described by the Sálim Ali Centre for Ornithology and Natural History (SACON) as a "precious germplasm."
Dai et al., 2012 discover
The genome of O. nivara was first sequenced in 2015.
Stein et al., 2018 sequenced the genomes of O. nivara and other domesticated and wild relatives. They produced reference assemblies and...
