Oryza rufipogon
Species of grass
From Wikipedia, the free encyclopedia
Oryza rufipogon is a species of flowering plant in the family Poaceae.[2][3] It is known as brownbeard rice,[4] wild rice,[5] and red rice.[5] In 1965, Oryza nivara was separated off from O. rufipogon. The separation has been questioned,[6] and now many sources consider O. nivara to be a synonym of O. rufipogon.[7] O. nivara may be treated as the annual form of O. rufipogon.[8]
| Oryza rufipogon | |
|---|---|
| |
Scientific classification  | |
| Kingdom: | Plantae |
| Clade: | Embryophytes |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Monocots |
| Clade: | Commelinids |
| Order: | Poales |
| Family: | Poaceae |
| Genus: | Oryza |
| Species: | O. rufipogon |
| Binomial name | |
| Oryza rufipogon | |
 | |
| The range of Oryza rufipogon. | |
| Synonyms[2] | |
| |
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.[8][9][10][11][12] Both have an AA genome.[13]
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.[11]
Genetics
Selection
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.[14]
Precious germplasm
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."[15]
Domestication
Dai et al., 2012 discover LHD1, an allele of DTH8/Ghd8.[16] Dai also finds LHD1 produces the late heading O. rufipogon phenotype.[16] This is one of the traits bred out during O. sativa domestication.[16]
Genome
The genome of O. nivara was first sequenced in 2015.[17]
Stein et al., 2018 sequenced the genomes of O. nivara and other domesticated and wild relatives.[18] They produced reference assemblies and analyses for divergence time and genetic distance.[18] (The O. nivara assembly is 338 Mb.) They demonstrated that this species and Oryza sativa subsp. indica are most closely related and that the same is true for Oryza sativa subsp. japonica and Oryza rufipogon.[18]
Invasive species
Oryza rufipogon is an invasive species and listed as a 'noxious weed' by the United States,[19] and listed as a noxious weed in Alabama, California, Florida, Massachusetts, Minnesota, North Carolina, Oregon, South Carolina, and Vermont. According to the NAPPO (North American Plant Protection Organization), O. rufipogon blends in with cultivated O. sativa so well that it cannot be detected. In this position it competes with the cultivated rice and uses valuable fertilizer and space. O. rufipogon sheds most of its seeds before the harvest, therefore contributing little to the overall yield. In addition, the rice grains produced by the plant are not eaten by consumers, who see it as a strange foreign particle in otherwise white rice.[20]
