Oryza glaberrima | |
---|---|
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Monocots |
Clade: | Commelinids |
Order: | Poales |
Family: | Poaceae |
Genus: | Oryza |
Species: | O. glaberrima |
Binomial name | |
Oryza glaberrima | |
Wild range. Cultivated range is much larger. |
Oryza glaberrima, commonly known as African rice, is one of the two domesticated rice species. [1] It was first domesticated and grown in West Africa around 3,000 years ago. [2] [3] In agriculture, it has largely been replaced by higher-yielding Asian rice ( O. sativa ), [2] and the number of varieties grown is declining. [1] It still persists, making up an estimated 20% [4] of rice grown in West Africa. It is now rarely sold in West African markets, having been replaced by Asian strains. [5]
In comparison to Asian rice, African rice is hardy, pest-resistant, low-labour, and suited to a larger variety of African conditions. [1] It is described as filling, with a distinct nutty flavour. [4] It is also grown for cultural reasons; for instance, it is sacred to followers of Awasena (a traditional African religion) among the Jola people, [6] and is a heritage variety in the United States. [7]
Crossbreeding between African and Asian rice is difficult, but there exist some crosses. [8] [9] [10] Jones et al. 1997 and Gridley et al. 2002 provide hybrids combining glaberrima's disease resistance and sativa's yield potential. [11]
This section needs additional citations for verification .(July 2021) |
It is highly likely that humans have independently domesticated two different rice species. African rice is very genetically similar to wild African rice ( O. barthii ), as Asian rice ( O. sativa ) is to wild Asian rice ( O. rufipogon ), and these two divisions have wide genetic differences between them.
O. barthii still grows wild in Africa, in a wide variety of open habitats. The Sahara was formerly wetter, with massive paleolakes in what is now the Western Sahara. As the climate dried, the wild rice retreated and probably became increasingly domesticated as it relied on humans for irrigation. Rice growing in deeper, more permanent water became floating rice. [4]
It was domesticated about 3000 years ago [12] in the inland delta of the Upper Niger River, in what is now Mali. [1] [2] It then spread through West Africa. It has also been recorded off the east coast of Africa, in the Zanzibar Archipelago. [4]
O. barthii seedheads shatter, while O. glaberrima does not shatter as much.
In the late fifteenth and sixteenth centuries, the Portuguese sailed to the Southern Rivers area in West Africa and wrote that the land was rich in rice. "[T]hey said they found the country covered by vast crops, with many cotton trees and large fields planted in rice ... the country looked to them as having the aspect of a pond (i.e., a marais)". The Portuguese accounts speak of the Falupo Jola, Landuma, Biafada, and Bainik growing rice. André Álvares de Almada wrote about the dike systems used for rice cultivation, [1] from which modern West African rice dike systems are descended.
African rice was brought to the Americas with the transatlantic slave trade, arriving in Brazil probably by the 1550s [3] and in the U.S. in 1784. [15] [ dubious – discuss ] The seed was carried as provisions on slave ships, [3] and the technology and skills needed to grow it were brought by enslaved rice farmers. Newly imported African slaves were marketed for their rice-growing skills, as the high price of rice made it a major cash crop. [13] Not all Africans came to the Americas with knowledge in rice growing, due to the vast variabilities in cultures and ethnicities, but the practice of cultivation was shared throughout the Carolina plantations, which allowed the enslaved people to develop a new sense of culture and made African rice the primary source of nutrition. [16] The tolerance of African rice for brackish water meant it could be grown on coastal deltas, [14] [17] as it was in West Africa.
There are numerous stories about how the rice came to North America, [18] including a slave smuggling grains in her hair [3] and a ship driven in to trade by a storm. [14] [19] African rice is a rare crop in Brazil, Guyana, El Salvador and Panama, but it is still occasionally grown there. [4] There are also native South American rices, which makes it hard to recognize the arrival of African rice in histories. [3]
Asian rice came to West Africa in the late 1800s, and by the late twentieth century had substantially supplanted native African rice. However, African rice was still used in specific, often marginal habitats, and preferred for its taste. [1] [4] Farmers may grow African rice to eat and Asian rice to sell, as African rice is not exported.
The 2007 food price shocks drove efforts to raise rice production. Rice-growing regions of Africa are generally net rice importers (partly due to a lack of good local rice-processing capacity) so price increases hurt. [20] Among the efforts to increase yield was the adoption of nerica cultivars, crossbred to specifications from local farmers using African rice varieties provided by local farmers. [1] These were bred during the 1990s and released in the early 21st century. [8] Results so far have been mixed; the nerica varieties are less hardy and more labour-intensive, and effects on real-world yields vary. Subsidies of nerica seeds have also been criticized for encouraging the loss of native varieties and reducing the independence of farmers. [10]
Multiple varieties of African rice are often grown so that the harvest is staggered. In this way, the harvest can be eaten fresh. Freshly harvested rice is moist, and can be puffed in fire, and eaten. Fried rice has a brownish color when fried; this is because of the husk which is green in color and turns brown when heated.[ clarification needed ][ citation needed ]
African rice can be prepared in much the same way as Asian rice, but has a distinct nutty flavor, for which it is favored in West Africa. [1] [21] African rice grains are often reddish in colour; some varieties are strongly aromatic, [4] other, like Carolina Gold, are not at all aromatic. [15]
African rice is also used in local traditional medicine. [21]
Overall, O. glaberrima is considered a much more desirable and healthier [22] choice in places like Nigeria by West African farmers, where it is used to make Ofada rice because of its high nutrition content, [23] despite being less popular than O. sativa cultivars (as of 2019 [update] ). [12]
African rice is a tall rice plant, usually under 120 centimetres (47 in) but up to 5 metres (16 feet) for floating varieties, which may also branch and root from higher stem nodes. [4] Generally, African rice has small, pear-shaped grain, reddish bran and green to black hulls, straight, simply-branched panicles, and short, rounded ligules. There are, however, exceptions, and it can be hard to distinguish from Asian rice. [1] [4] For complete certainty, a genetic test can be used. [24]
Grains are brittle. [12]
African rice is well adapted to the African environment. It is drought- and deep-water-resistant, and tolerates fluctuations in water depth, iron toxicity, infertile soils, severe climatic conditions, and human neglect better than Asian rice. [1] [25] Some varieties also mature more quickly, and may be sown directly on higher ground, eliminating the need to transplant seedlings. [1] Most are rain-watered, and the soil is often not cultivated. [4]
African rice has profuse vegetative growth, which smothers weeds. It exhibits better resistance to various rice pests and diseases, such as blast disease, African rice gall midge ( Orseolia oryzivora ), parasitic nematodes ( Heterodera sacchari and Meloidogyne spp.), rice stripe necrosis virus (a Benyvirus ), rice yellow mottle virus , and the parasitic plant Striga . [8] [25]
African rices shatter more than Asian rices, [12] possibly because they have not been domesticated for as long. A few varieties of African rice are as resistant to shattering as shatter-resistant Asian varieties, but most are not; on average, about half of the grains are scattered and lost. This is why yield is lower; when the heads of African rice are bagged before they become ripe, so that the shattered grains are caught in paper bags, the yield of African rice is the same as the yield of Asian rice. [25]
Like other grains, rice may lodge, or fall over, when grain heads are full. African rice's greater height and weaker stems makes it more likely to lodge, although it also lets it survive in deep water, and makes it easier to harvest. African rice tends to elongate rapidly if completely submerged, which is not advantageous in regions prone to short floods, as it weakens the plant. [4] [26]
The grains of African rice are more brittle than those of Asian rice. The grains are more likely to break during industrial polishing. [7] Broken rice is widely used in West Africa, and some cookbooks from the region will suggest manually breaking the grains for certain recipes, [27] but most broken rice eaten is from Asian rice, about 16% of which is broken in processing.[ citation needed ]
The genome of O. glaberrima has been sequenced, and was published in 2014. [2] This allowed genomic as well as physiological comparison with related species, and identified some effects of some genes. [28] [29]
African and Asian rice do not readily interpollinate, even under controlled conditions, and when they do, the offspring are very rarely fertile. Even the fertile crossbred offspring have low fertility. [8]
Crossbreeding seems to have succeeded in at least one area of Maritime Guinea, as some varieties there show crossbred genes. [9]
More recently, the nerica cultivars (new rice for Africa) have been developed using green revolution techniques like embryo rescue. [8] Over 3000 crosses were made as part of the NERICA program. [8] Breeding within the species is easier, and there are uncounted numbers of African rice varieties, although the majority may have been lost. [1] A similar crossed variety was bred in the United States in 2011, [18] and work is being done on crosses with Indian rice varieties. [8]
There are a great many varieties of African rice. In the 1960s older women in Jipalom (Ziguinchor Region, Senegal) could unhesitatingly name more than ten varieties of African rice that were no longer planted, besides the half-dozen that were then still being planted. Each woman would plant multiple different varieties, to suit varying microhabitats and to stagger the harvest. [1] A 2006 survey showed that a village typically cultivated 25 varieties of rice; an individual household would on average have 14 varieties and grow four per year; [10] this, however, is down from the seven to nine varieties per woman that was average in previous decades. Women, who are traditionally responsible for the seeds, trade them often over long-distance networks. [1]
Varieties, each with subtypes, include: [1]
The cultivars the Africa Rice Center calls TOG 12303 and TOG 9300 have low shattering, and thus yields comparable with low-shattering Asian rice varieties. [25]
Scientists from the Africa Rice Center managed to cross-breed African rice with Asian rice varieties to produce a group of interspecific cultivars called New Rice for Africa (NERICA). [30]
Carolina Gold is an heirloom cultivar grown in the early United States, sometimes known as golden-seed rice for the colour of its grains. [15]
Long-grain gold-seed rice boasted grains 5⁄12 inch (11 mm)inch long (up 11% from 3⁄8 inch (9.5 mm)), and was brought to market by planter Joshua John Ward in the 1840s. Despite its popularity, the variety was lost in the American Civil War. [15]
Charleston Gold was released in 2011 and is a crossbreed of Carolina Gold and two breeding lines of O. s. indica called IR64 [31] and IR65610-24-3-6-3-2-3 (a dwarf, fragrant breeding line), which raised the yield, shortened the stem, and added an aromatic quality to the rice. [15] IR 64 Parboiled Rice 5% Broken is most famous and demanding rice in West African countries like Ghana, Togo, Benin etc. [32]
Rice is a cereal grain and in its domesticated form is the staple food of over half of the world's population, particularly in Asia and Africa. Rice is the seed of the grass species Oryza sativa —or, much less commonly, Oryza glaberrima. Asian rice was domesticated in China some 13,500 to 8,200 years ago; African rice was domesticated in Africa about 3,000 years ago. Rice has become commonplace in many cultures worldwide; in 2021, 787 million tons were produced, placing it fourth after sugarcane, maize, and wheat. Only some 8% of rice is traded internationally. China, India, and Indonesia are the largest consumers of rice. A substantial amount of the rice produced in developing nations is lost after harvest through factors such as poor transport and storage. Rice yields can be reduced by pests including insects, rodents, and birds, as well as by weeds, and by diseases such as rice blast. Traditional rice polycultures such as rice-duck farming, and modern integrated pest management seek to control damage from pests in a sustainable way.
Oryza is a genus of plants in the grass family. It includes the major food crop rice. Members of the genus grow as tall, wetland grasses, growing to 1–2 metres (3–7 ft) tall; the genus includes both annual and perennial species.
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.
New Rice for Africa (NERICA) is a cultivar group of interspecific hybrid rice developed by the Africa Rice Center (AfricaRice) to improve the yield of African rice cultivars. Although 240 million people in West Africa rely on rice as the primary source of food energy and protein in their diet, the majority of this rice is imported. Self-sufficiency in rice production would improve food security and aid economic development in West Africa.
The Africa Rice Center (AfricaRice), formerly known as the West Africa Rice Development Association (WARDA), is a pan-African intergovernmental association and a CGIAR Research organization, currently headquartered in Abidjan, Côte d'Ivoire. AfricaRice is an agricultural research center that was constituted in 1971 by 11 West African countries. By 2023, the center counted 28 African member states. Since 1986, AfricaRice has been one of the 15 specialized research centers of CGIAR.
Monty Jones was a Sierra Leonean plant breeder and politician who served as the Minister of Agriculture, Forestry and Food Security.
Broken rice is fragments of rice grains, broken in the field, during drying, during transport, or during milling. Mechanical separators are used to separate the broken grains from the whole grains and sort them by size.
Oryza barthii, also called Barth's rice, wild rice, or African wild rice, is a grass in the rice genus Oryza. It is an annual, erect to semierect grass. It has leaves with a short ligule, and panicles that are compact to open, rarely having secondary branching. The inflorescence structure are large spikelets, 7.7–12.3 millimetres long and 2.3–3.5 millimetres wide, with strong awns, usually red. The inflorescences have anthers 1.5–3 millimetres long.
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 some sources consider O. nivara to be a synonym of O. rufipogon. O. nivara may be treated as the annual form of O. rufipogon.
Oryza longistaminata is a perennial species of grass from the same genus as cultivated rice. It is native to most of sub-Saharan Africa and Madagascar. It has been introduced into the United States, where it is often regarded as a noxious weed. Its common names are longstamen rice and red rice.
A crop wild relative (CWR) is a wild plant closely related to a domesticated plant. It may be a wild ancestor of the domesticated (cultivated) plant or another closely related taxon.
Oryza nivara is a possible wild progenitor of the cultivated rice Oryza sativa. It was separated from Oryza rufipogon in 1965; however, the separation has been questioned, and some sources treat it as a synonym of O. rufipogon. It may be treated as the annual form of O. rufipogon.
Japonica rice, sometimes called sinica rice, is one of the two major domestic types of Asian rice varieties. Japonica rice is extensively cultivated and consumed in East Asia, whereas in most other regions indica rice is the dominant type of rice. Japonica rice originated from Central China, where it was first domesticated along the Yangtze River basin approximately 9,500 to 6,000 years ago.
Rice production in China is the amount of rice planted, grown, and harvested for consumption in the mainland of China.
Perennial rice are varieties of long-lived rice that are capable of regrowing season after season without reseeding; they are being developed by plant geneticists at several institutions. Although these varieties are genetically distinct and will be adapted for different climates and cropping systems, their lifespan is so different from other kinds of rice that they are collectively called perennial rice. Perennial rice—like many other perennial plants—can spread by horizontal stems below or just above the surface of the soil but they also reproduce sexually by producing flowers, pollen and seeds. As with any other grain crop, it is the seeds that are harvested and eaten by humans.
Plant breeding started with sedentary agriculture, particularly the domestication of the first agricultural plants, a practice which is estimated to date back 9,000 to 11,000 years. Initially, early human farmers selected food plants with particular desirable characteristics and used these as a seed source for subsequent generations, resulting in an accumulation of characteristics over time. In time however, experiments began with deliberate hybridization, the science and understanding of which was greatly enhanced by the work of Gregor Mendel. Mendel's work ultimately led to the new science of genetics. Modern plant breeding is applied genetics, but its scientific basis is broader, covering molecular biology, cytology, systematics, physiology, pathology, entomology, chemistry, and statistics (biometrics). It has also developed its own technology. Plant breeding efforts are divided into a number of different historical landmarks.
Rice production is the fourth largest among cereals in the United States, after corn, wheat, and sorghum. Of the country's row crop farms, rice farms are the most capital-intensive and have the highest national land rental rate average. In the United States, all rice acreage requires irrigation. In 2000–09, approximately 3.1 million acres in the United States were under rice production; an increase was expected over the next decade, to approximately 3.3 million acres. USA Rice represents rice producers in the six largest rice-producing states of Arkansas, California, Louisiana, Mississippi, Missouri, and Texas.
The history of rice cultivation is an interdisciplinary subject that studies archaeological and documentary evidence to explain how rice was first domesticated and cultivated by humans, the spread of cultivation to different regions of the planet, and the technological changes that have impacted cultivation over time.
The agricultural weed syndrome is the set of common traits which make a plant a successful agricultural weed. Most of these traits are not, themselves, phenotypes but are instead methods of rapid adaptation. So equipped, plants of various origins - invasives, natives, mildly successful marginal weeds of agriculture, weeds of other settings - accumulate other characteristics which allow them to compete in an environment with a high degree of human management.
Arroz de fríjol cabecita negra is a rice-based dish from the Caribbean Coast of Colombia that utilizes black-eyed peas as the legume, differing from other rice dishes that are usually prepared with different legumes such as beans, peas, lentils, and Pigeon peas.
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