View source for Oryza glaberrima

{{Short description|African rice, second most common rice}}
{{speciesbox
|image = Oryza glaberrima seeds.jpg
|image_alt = Seeds
|genus = Oryza
|species = glaberrima
|authority = [[Steud.]]
|range_map = Oryza glaberrima distribution.svg
|range_map_caption = Wild range. [[Cultivated range]] is much larger.
}}
'''''Oryza glaberrima''''', commonly known as '''African rice''', is one of the two domesticated [[rice]] species.<ref name=linares>{{Cite journal| doi = 10.1073/pnas.252604599|issn=1091-6490| volume = 99| issue = 25| pages = 16360–16365| last = Linares| first = Olga F.| title = African rice (''Oryza glaberrima''): History and future potential| journal = [[Proceedings of the National Academy of Sciences]] | date = 2002-12-10| pmid = 12461173| pmc=138616|bibcode=2002PNAS...9916360L|doi-access=free}}</ref> It was first domesticated and grown in [[West Africa]] around 3,000 years ago.<ref name=genome/><ref name=carney/> In agriculture, it has largely been replaced by higher-yielding Asian rice (''[[Oryza sativa|O. sativa]]''),<ref name=genome/> and the number of varieties grown is declining.<ref name=linares/> It still persists, making up an estimated 20%<ref name=PROT4U/> of rice grown in West Africa. It is now rarely sold in West African markets, having been replaced by Asian strains.<ref name=vanguard>{{cite news|title=Smuggled rice floods Nigerian market, as merchants suffer losses|periodical=[[Vanguard (Nigeria)|Vanguard]]|date=2013-10-07|first1=Sunny|last1=Ikhioya|first2=Godwin|last2=Oritse|url=http://www.vanguardngr.com/2013/10/smuggled-rice-floods-nigerian-market-merchants-suffer-losses/fsale}}{{Dead link|date=April 2020 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> 

In comparison to Asian rice, African rice is hardy, pest-resistant, low-labour, and suited to a larger variety of African conditions.<ref name=linares/> It is described as filling, with a distinct nutty flavour.<ref name=PROT4U/> It is also grown for cultural reasons; for instance, it is sacred to followers of [[Awasena]] (a [[traditional African religion]]) among the [[Jola people]],<ref>{{Cite book|chapter=Senegal: Modern Senegalese Recipes from the Source to the Bowl|title=A System of Rice Production, Broken|first1=Pierre|last1=Thiam|first2=Jennifer|last2=Sit|publisher=Lake Isle Press|date=2015|url=http://www.southernfoodways.org/a-system-of-rice-production-broken}}</ref> and is [[#American_cultivars|a heritage variety]] in the United States.<ref name=blackrice/>

Crossbreeding between African and Asian rice is difficult, but there exist some crosses.<ref name=india/><ref name=cross/><ref name=ngo>{{cite web |author= [[GRAIN]] |title=Nerica: another trap for small farmers in Africa|date=2009|url=https://www.grain.org/article/entries/111-nerica-another-trap-for-small-farmers-in-africa.pdf}}</ref> Jones ''et al.'' 1997 and Gridley ''et al.'' 2002 provide [[hybrid (biology)|hybrid]]s combining ''glaberrima''{{'}}s [[crop disease resistance|disease resistance]] and ''sativa''{{'}}s [[crop yield|yield]] potential.<ref name = "Complex-History" >
{{ Cite journal
 | year = 2007
 | publisher = [[Oxford University Press]]
 | volume = 100
 | first1 = Megan
 | last1 = Sweeney
 | first2 = Susan
 | last2 = McCouch
 | pages = 951–957
 | journal = [[Annals of Botany]]
 | s2cid = 14266565
 | doi = 10.1093/aob/mcm128
 | title = The Complex History of the Domestication of Rice
| issue = 5
 | pmid = 17617555
 | pmc = 2759204
 }}</ref>

== History ==
{{More citations needed|section|date=July 2021}}
[[File:African rice niger.png|thumb|Growing along the [[Niger River]], where the species was first domesticated
]]
It is highly likely that humans have independently domesticated two different rice species. African rice is very genetically similar to wild African rice (''[[Oryza barthii|O. barthii]]''), as Asian rice (''[[Oryza sativa|O. sativa]]'') is to wild Asian rice (''[[Oryza rufipogon|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 [[North African climate cycles|formerly wetter]], with massive [[paleolake]]s 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]].<ref name=PROT4U>{{cite web|author=[[Plant Resources of Tropical Africa]]|title=''Oryza glaberrima'' Steud|url=http://www.prota4u.org/protav8.asp?p=Oryza+glaberrima|access-date=2016-08-10|archive-date=2016-11-05|archive-url=https://web.archive.org/web/20161105173559/http://www.prota4u.org/protav8.asp?p=Oryza+glaberrima|url-status=dead }}</ref>

[[File:Map of River Niger.svg|frameless|left
]]
It was domesticated about 3000 years ago<ref name="Chen-et-al-2019">{{cite journal | last1=Chen | first1=Erwang | last2=Huang | first2=Xuehui | last3=Tian | first3=Zhixi | last4=Wing | first4=Rod A. | last5=Han | first5=Bin | title=The Genomics of ''Oryza'' Species Provides Insights into Rice Domestication and Heterosis | journal=[[Annual Review of Plant Biology]] | publisher=[[Annual Reviews (publisher)|Annual Reviews]] | volume=70 | issue=1 | date=2019-04-29 | issn=1543-5008 | doi=10.1146/annurev-arplant-050718-100320 | pages=639–665| pmid=31035826 | s2cid=140266038 }}</ref> in the [[Inner Niger Delta|inland delta]] of the Upper [[Niger River]], in what is now [[Mali]].<ref name=linares/><ref name=genome>
:{{cite journal|last1=Wendel|first1=Jonathan F.|last2=Jackson|first2=Scott A.|last3=Meyers|first3=Blake C.|last4=Wing|first4=Rod A.|s2cid=12325319|title=Evolution of plant genome architecture|journal=[[Genome Biology]]|publisher=[[BioMed Central Ltd]]|volume=17|issue=1|date=2016-03-01|page=37 |issn=1474-760X|doi=10.1186/s13059-016-0908-1|pmid=26926526 |pmc=4772531 |doi-access=free }}
:
:{{cite book|series=[[Methods in Molecular Biology]] (MIMB)|title=Plant Bioinformatics|publisher=[[Humana New York, NY]]|publication-place=[[New York, NY]]|year=2016|volume=1374 |isbn=978-1-4939-3166-8|issn=1064-3745|doi=10.1007/978-1-4939-3167-5|pages=115–140}}
:
:These reviews cite this research.
:
:{{Cite journal| doi = 10.1038/ng.3044| issn = 1061-4036| volume = 46| issue = 9| pages = 982–988| last1 = Wang| first1 = Muhua| last2 = Yu| first2 = Yeisoo| last3 = Haberer| first3 = Georg| last4 = Marri| first4 = Pradeep Reddy| last5 = Fan| first5 = Chuanzhu| last6 = Goicoechea| first6 = Jose Luis| last7 = Zuccolo| first7 = Andrea| last8 = Song| first8 = Xiang| last9 = Kudrna| first9 = Dave| last10 = Ammiraju| first10 = Jetty S. S.| last11 = Cossu| first11 = Rosa Maria| last12 = Maldonado| first12 = Carlos| last13 = Chen| first13 = Jinfeng| last14 = Lee| first14 = Seunghee| last15 = Sisneros| first15 = Nick| last16 = de Baynast| first16 = Kristi| last17 = Golser| first17 = Wolfgang| last18 = Wissotski| first18 = Marina| last19 = Kim| first19 = Woojin| last20 = Sanchez| first20 = Paul| last21 = Ndjiondjop| first21 = Marie-Noelle| last22 = Sanni| first22 = Kayode| last23 = Long| first23 = Manyuan| last24 = Carney| first24 = Judith| last25 = Panaud| first25 = Olivier| last26 = Wicker| first26 = Thomas| last27 = Machado| first27 = Carlos A.| last28 = Chen| first28 = Mingsheng| last29 = Mayer| first29 = Klaus F. X.| last30 = Rounsley| first30 = Steve| last31 = Wing| first31 = Rod A.| title = The genome sequence of African rice (''Oryza glaberrima'') and evidence for independent domestication| journal = [[Nature Genetics]] |date = 2014-07-27| pmid=25064006| pmc = 7036042| doi-access = free}}</ref> It then spread through West Africa. It has also been recorded off the ''east'' coast of Africa, in the [[Zanzibar Archipelago]].<ref name=PROT4U/>

''O. barthii'' seedheads [[Shattering (agriculture)|shatter]], while ''O. glaberrima'' does not shatter as much.

[[File:Carabane-Digue.jpg|thumb|240px|right|alt=A pond in the foreground with a steep embankment blocking its spreading to the left and with trees in the background|[[Karabane]], Senegal, 2008. Dikes protect the rice paddy fields from saltwater; the irrigation skims the [[Estuarine water circulation#Salt wedge estuary|freshwater layer]] off the high tide.<ref name=Slavery>{{Cite web|url=http://slaveryinamerica.org/history/hs_es_rice.htm |title=Rice and Slavery: A Fatal Gold Seede |author=Jean M. West |access-date=24 June 2013 |publisher=[[Slavery in America Organization]]|url-status=dead |archive-url=https://web.archive.org/web/20070101092714/http://slaveryinamerica.org/history/hs_es_rice.htm |archive-date=January 1, 2007 }}</ref> Similar delta cultivation techniques were used going back to at least the 15th century in [[South Carolina]].<ref name=southcaro>{{Cite web|title=Slavery on South Carolina Rice Plantations: The Migration of People and Knowledge in Early Colonial America|url=https://ricediversity.org/outreach/educatorscorner/documents/Carolina-Gold-Student-handout.pdf|author=The Rice Diversity Project]|access-date=2016-08-09|archive-url=https://web.archive.org/web/20150702053521/http://ricediversity.org/outreach/educatorscorner/documents/Carolina-Gold-Student-handout.pdf|archive-date=2015-07-02|url-status=dead}}</ref>
]]
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. "{{bracket|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 people|Jola]], [[Landoma language|Landuma]], [[Biafada]], and [[Bainuk people|Bainik]] growing rice. [[André Álvares de Almada]] wrote about the [[dike (construction)|dike]] systems used for rice cultivation,<ref name=linares/> from which [[Carabane#Rice cultivation|modern West African rice dike systems]] are descended.

[[File:Hampton-plantation-rice-dike-sc1.jpg|thumb|left|Similar dyke, [[Hampton Plantation]], 2010, long abandoned and reclaimed by woodland<ref name=southcaro/>
]]
African rice was brought to the Americas with the [[transatlantic slave trade]], arriving in Brazil probably by the 1550s<ref name=carney/> and in the U.S. in 1784.<ref name=charleston/>{{dubious|date=August 2016}} The seed was carried as provisions on slave ships,<ref name=carney/> 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.<ref name=Slavery/> 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.<ref>{{Cite book|last=Carney|first=Judith A.|url=http://dx.doi.org/10.2307/j.ctvjz837d|title=Black Rice|date=2009-06-30| publisher = [[Harvard University Press]] |isbn=978-0-674-02921-7|pages=5|doi=10.2307/j.ctvjz837d|s2cid=247120906 }}</ref> The tolerance of African rice for brackish water meant it could be grown on coastal deltas,<ref name=southcaro/><ref>{{cite web|url=http://ldhi.library.cofc.edu/exhibits/show/forgotten_fields/decline_in_inland_rice|title=Decline in Inland Rice Production · Forgotten Fields: Inland Rice Plantations in the South Carolina Lowcountry · Lowcountry Digital History Initiative|website=ldhi.library.cofc.edu|access-date=8 June 2018}}</ref> as it was [[Carabane#Rice cultivation|in West Africa]].

There are numerous stories about how the rice came to North America,<ref name=goldenseed>{{Cite news|url=http://www.carolinagoldricefoundation.org/papers/ricepaper.5.1.2011.pdf|title=The Golden Seed|author=David S. Shields|periodical=Rice Paper|volume=5|number=1|access-date=2016-08-09|archive-date=2018-05-13|archive-url=https://web.archive.org/web/20180513080911/http://www.carolinagoldricefoundation.org/papers/ricepaper.5.1.2011.pdf|url-status=dead}}</ref> including a slave smuggling grains in her hair<ref name=carney>{{cite journal |title='With Grains in Her Hair': Rice in Colonial Brazil|author=Judith A. Carney|url=http://www.sscnet.ucla.edu/geog/downloads/594/33.pdf|journal=[[Slavery and Abolition]]|volume=25|number=1|year=2004|pages=1–27|publisher=[[Frank Cass]]|location=[[London]]|doi=10.1080/0144039042000220900|s2cid=3490844|access-date=2016-08-09|archive-url=https://web.archive.org/web/20161105174045/http://www.sscnet.ucla.edu/geog/downloads/594/33.pdf|archive-date=2016-11-05|url-status=dead}}</ref> and a ship driven in to trade by a storm.<ref name=southcaro/><ref>{{cite web|url=http://www.carolinaplantationrice.com/history/|title=Rice History - Carolina Plantation Rice|website=www.carolinaplantationrice.com|access-date=8 June 2018}}</ref> African rice is a rare crop in Brazil, Guyana, El Salvador and Panama, but it is still occasionally grown there.<ref name=PROT4U/> There are also native South American rices, which makes it hard to recognize the arrival of African rice in histories.<ref name=carney/>

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.<ref name=linares/><ref name=PROT4U/> 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.<ref>{{cite conference|url=http://www.africarice.org/workshop/ARC/3.4%20Tiamiyu%20fin.pdf|title=Assessment of quality management techniques: Toward improving competitiveness of Nigerian rice|first1=S.A.|last1=Tiamiyu|first2=S.A|last2=Usman|first3=A.|last3=Gbanguba|first4=A.U.|last4=Ukwungu|first5=M.N.|last5=Ochigbo|first6=A.A.|last6=Ochigbo|conference=Second [[Africa Rice Congress]]: Innovation and Partnerships to Realize Africa's Rice Potential|date=2010|location=[[Bamako, Mali]]|access-date=2016-08-10|archive-date=2017-08-09|archive-url=https://web.archive.org/web/20170809080041/http://www.africarice.org/workshop/ARC/3.4%20Tiamiyu%20fin.pdf|url-status=dead}}</ref> Among the [[yield breeding|efforts to increase yield]] was the adoption of ''[[nerica]]'' cultivars, crossbred to specifications from local farmers using African rice varieties provided by local farmers.<ref name=linares/> These were bred during the 1990s and released in the early 21st century.<ref name=india/> 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.<ref name=ngo/>

== Uses ==
{|style="margin: 0 auto;"name-handout
| [[File:Reis - Sorte C roh.jpg|thumb|left|With inedible husk
]]
| [[File:Reis - Sorte C voll.jpg|thumb|left|Dehusked (whole [[brown rice]])
]]
| [[File:Reis_-_Sorte_C_weiss.jpg|thumb|left|[[Bran]] and [[cereal germ|germ]] removed ([[white rice]])
]]
|}
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 rice|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.{{clarify|reason=Is the rice puffed by roasting it in its husk, which turns brown?|date=August 2016}}{{citation needed|date=August 2016}}

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.<ref name=linares/><ref name=kew>{{Cite web| title = ''Oryza glaberrima'' (African rice) |publisher=Plants & Fungi At [[Kew Gardens]]| access-date = 2016-08-10| url = http://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:410061-1}}</ref> African rice grains are often reddish in colour; some varieties are strongly aromatic,<ref name=PROT4U/> other, like Carolina Gold, are not at all aromatic.<ref name=charleston/>

African rice is also used in local traditional medicine.<ref name=kew/>

== Traits ==
Overall, ''O. glaberrima'' is considered a much more desirable and healthier<ref name="ofada">{{ Cite journal |year=2019|issue=1|volume=6|publisher=[[Springer Science and Business Media LLC]]|first2=Lloyd|first1=A.|journal=[[Journal of Ethnic Foods]]|issn=2352-6181|last1=Ogunleke|last2=Baiyegunhi|title=Effect of households' dietary knowledge on local (ofada) rice consumption in southwest Nigeria|doi=10.1186/s42779-019-0023-5|s2cid=257164894|doi-access=free}}</ref> choice in places like Nigeria by West African farmers, where it is used to make [[Ofada rice]] because of its high nutrition content,<ref>{{cite web |last1=George |first1=Bunmi |title=Ofada rice the super food |url=https://guardian.ng/features/ofada-rice-the-super-food/#:~:text=Ofada%20rice%20is%20so%20nutritious,energy%20and%20nurture%20your%20bones. |work=[[The Guardian (Nigeria)|The Guardian]] |date=15 September 2016 |access-date=7 February 2023}} despite </ref> despite being less popular than ''O. sativa'' cultivars ({{as of|2019|lc=yes}}).<ref name="Chen-et-al-2019" />

=== Appearance ===
African rice is a tall rice plant, usually under {{Convert|120|cm}} but up to {{Convert|5|m|abbr=off}} for [[floating rice|floating]] varieties, which may also branch and root from higher stem nodes.<ref name=PROT4U/> Generally, African rice has small, pear-shaped grain, reddish bran and green to black [[rice hull|hulls]], straight, simply-branched [[panicles]], and short, rounded [[ligules]]. There are, however, exceptions, and it can be hard to distinguish from Asian rice.<ref name=linares/><ref name=PROT4U/> For complete certainty, a genetic test can be used.<ref>{{cite book |last=Nourollah |first=Ahmadi  |date=2016 |url=http://link.springer.com/10.1007/978-3-319-25954-3_2 |title=Genetic Diversity and Erosion in Plants |chapter=Genetic Diversity, Genetic Erosion, and Conservation of the Two Cultivated Rice Species (''Oryza sativa'' and ''Oryza glaberrima'') and Their Close Wild Relatives |series=Sustainable Development and Biodiversity |volume=8 |pages=35–73 |editor-last=Ahuja |editor-first=M.R. |place=Cham |publisher=Springer International Publishing |doi=10.1007/978-3-319-25954-3_2 |isbn=978-3-319-25953-6 |access-date=2023-02-23 |editor2-last=Jain |editor2-first=S. Mohan}}</ref>

=== Grain qualities ===
Grains are brittle.<ref name="Chen-et-al-2019" />

=== Hardiness ===
African rice is well adapted to the African environment. It is drought- and [[deepwater rice|deep-water]]-resistant, and tolerates fluctuations in water depth, iron toxicity, infertile soils, severe climatic conditions, and human neglect better than Asian rice.<ref name=linares/><ref name=shatter>{{Cite journal| doi = 10.4314/ijbcs.v7i2.10| issn = 1997-342X| volume = 7| issue = 2| pages = 535–543| last1 = Montcho| first1 = D.| last2 = Futakuchi| first2 = K.| last3 = Agbangla| first3 = C.| last4 = Fofana| first4 = M.| last5 = Dieng| first5 = I.| title = Yield loss of ''Oryza glaberrima'' caused by grain shattering under rainfed upland conditions| journal =[[International Journal of Biological and Chemical Sciences]]| date = 2013-01-01| doi-access = free}}</ref> Some varieties also mature more quickly, and may be sown directly on higher ground, eliminating the need to transplant seedlings.<ref name=linares/> Most are rain-watered, and the soil is often not cultivated.<ref name=PROT4U/>

African rice has profuse vegetative growth, which smothers weeds. It exhibits better resistance to various [[List of rice diseases|rice pests and diseases]], such as [[blast disease]], African rice gall midge (''[[Orseolia oryzivora]]''), parasitic [[nematode]]s (''[[Heterodera sacchari]]'' and ''[[Meloidogyne]]'' spp.), ''[[rice stripe necrosis virus]]'' (a ''[[Benyvirus]]''), ''[[rice yellow mottle virus]]'', and the parasitic plant ''[[Striga (plant)|Striga]]''.<ref name=india/><ref name=shatter/>

=== Yield and processing ===
African rices [[shattering (agriculture)|shatter]] more than Asian rices,<ref name="Chen-et-al-2019" /> possibly because they have not [[rice domestication|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.<ref name=shatter/>

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 [[deepwater rice|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.<ref name=PROT4U/><ref>{{Cite book| publisher =[[Academic Press]]| isbn = 978-0-12-005907-2| last = Woolhouse| first = Harold William| title =[[Advances in Botanical Research]]|volume=7| location = [[London]] | date = 1979}}</ref>

The grains of African rice are more brittle than those of Asian rice. The grains are more likely to break during industrial polishing.<ref name=blackrice>{{Cite book| publisher =[[Harvard University Press]] | isbn = 978-0-674-02921-7| last1 = Carney| first1 = Judith Ann| title = Black Rice: The African Origins of Rice Cultivation in the Americas| date = 2009-06-30|url=https://www.nytimes.com/books/first/c/carney-rice.html}}</ref> [[Broken rice]] is widely used in West Africa, and some cookbooks from the region will suggest manually breaking the grains for certain recipes,<ref>{{Cite web |url=http://congocookbook.com/rice_recipes/ceebu_jen.html |title=example |access-date=2016-08-10 |archive-date=2016-11-05 |archive-url=https://web.archive.org/web/20161105171605/http://congocookbook.com/rice_recipes/ceebu_jen.html |url-status=dead }}</ref> but most broken rice eaten is from Asian rice, about 16% of which is broken in processing.{{Cn|date=July 2021}}

The genome of ''O. glaberrima'' has been sequenced, and was published in 2014.<ref name=genome/> This allowed genomic as well as physiological comparison with related species, and identified some effects of some genes.<ref name=diversification>{{Cite journal| doi = 10.1073/pnas.1418307111| issn = 1091-6490| volume = 111| issue = 46| pages =E4954–E4962| last1 = Zhang| first1 = Qun-Jie| last2 = Zhu| first2 = Ting| last3 = Xia| first3 = En-Hua| last4 = Shi| first4 = Chao| last5 = Liu| first5 = Yun-Long| last6 = Zhang| first6 = Yun| last7 = Liu| first7 = Yuan| last8 = Jiang| first8 = Wen-Kai| last9 = Zhao| first9 = You-Jie| last10 = Mao| first10 = Shu-Yan| last11 = Zhang| first11 = Li-Ping| last12 = Huang| first12 = Hui| last13 = Jiao| first13 = Jun-Ying| last14 = Xu| first14 = Ping-Zhen| last15 = Yao| first15 = Qiu-Yang| last16 = Zeng| first16 = Fan-Chun| last17 = Yang| first17 = Li-Li| last18 = Gao| first18 = Ju| last19 = Tao| first19 = Da-Yun| last20 = Wang| first20 = Yue-Ju| last21 = Bennetzen| first21 = Jeffrey L.| last22 = Gao| first22 = Li-Zhi| title = Rapid diversification of five ''Oryza'' AA genomes associated with rice adaptation| journal = [[Proceedings of the National Academy of Sciences]] | date = 2014-11-18| pmid = 25368197| pmc=4246335| bibcode = 2014PNAS..111E4954Z| doi-access = free}}</ref><ref name = "Identification-of-Locus" >
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 |bibcode =2010Rice....3..218A
 }}
 |...cite this study:
 |{{*}} {{ Cite journal
 |last1 =Gutierrez| first1 =Andres
 |last2 =Carabali| first2 =Silvio
 |last3 =Giraldo| first3 =Olga
 |last4 =Martinez| first4 =Cesar
 |last5 =Correa| first5 =Fernando
 |last6 =Prado| first6 =Gustavo
 |last7 =Tohme| first7 =Joe
 |last8 =Lorieux| first8 =Mathias
 |year =2010
 |title =Identification of a ''Rice stripe necrosis virus'' resistance locus and yield component QTLs using ''Oryza sativa'' × ''O. glaberrima'' introgression lines
 |journal =[[BMC Plant Biology]]
 |publisher =[[BioMed Central]]
 |volume =10 |page =1–11
 |issn =1471-2229
 |pmid =20064202
 |pmc =2824796
 |s2cid =13794259
 |doi =10.1186/1471-2229-10-6
 |doi-access =free
 |language =en
}}
 }}
</ref>

=== Breeding ===
African and Asian rice do not readily interpollinate, even under [[selective breeding|controlled conditions]], and when they do, the offspring are very rarely fertile. Even the fertile crossbred offspring have low fertility.<ref name=india/>

[[Crossbreeding]] seems to have succeeded in at least one area of Maritime [[Guinea (country)|Guinea]], as some varieties there show crossbred genes.<ref name=cross>{{Cite journal| doi = 10.1007/s10681-006-9278-1| issn = 0014-2336| volume = 154| issue = 1–2| pages = 127–137| last1 = Barry| first1 = M. B.| last2 = Pham| first2 = J. L.| last3 = Noyer| first3 = J. L.| last4 = Billot| first4 = C.| last5 = Courtois| first5 = B.| last6 = Ahmadi| first6 = N.| title = Genetic diversity of the two cultivated rice species (''O. sativa'' & ''O. glaberrima'') in Maritime Guinea. Evidence for interspecific recombination| journal = [[Euphytica]] | date = 2007-01-04| s2cid = 23798032}}</ref>

More recently, the [[NERICA|''nerica'' cultivars]] ('''ne'''w '''ri'''ce for Afri'''ca''') have been developed using [[green revolution]] techniques like [[embryo rescue]].<ref name=india/> Over 3000 crosses were made as part of the NERICA program.<ref name=india/> Breeding within the species is easier, and there are uncounted numbers of African rice varieties, although the majority may have been lost.<ref name=linares/> A similar crossed variety was bred in the United States in 2011,<ref name=goldenseed/> and work is being done on crosses with Indian rice varieties.<ref name=india>{{Cite journal|publisher=[[Indian Academy of Sciences]]|issn = 0011-3891 | last1 = Sarla| first1 = N.| last2 = Swamy| first2 = B. P. Mallikarjuna| title = ''Oryza glaberrima'': A source for the improvement of ''Oryza sativa''|id=[[Current Science Association]]|journal =[[Current Science]]|volume=89 |issue=6 |pages=955–963 | access-date = 2016-08-10| date = 2005-09-25| url = https://www.researchgate.net/publication/228623310}}</ref>

== Cultivars ==
=== African cultivars ===
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 [[microhabitat]]s and to stagger the harvest.<ref name=linares/> 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;<ref name=ngo/> 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.<ref name=linares/>

Varieties, each with subtypes, include:<ref name=linares/>
* ''aspera'' ([[Latin]]: "rough")
* ''ebenicolorata'' ("ebony-colored")
* ''evoluta'' ("unfolded")
* ''rigida'' ("rigid")
* ''rustica'' ("coarse")

The cultivars the [[Africa Rice Center]] calls {{ Visible anchor |TOG 12303}} and {{ Visible anchor |TOG 9300}} have low [[shattering (agriculture)|shattering]], and thus yields comparable with low-shattering Asian rice varieties.<ref name=shatter/>

Scientists from the [[Africa Rice Center]] managed to cross-breed African rice with Asian rice varieties to produce a [[Cultivar group|group of interspecific cultivars]] called [[New Rice for Africa]] (NERICA).<ref>{{Cite journal|title = Interspecific ''Oryza Sativa'' L. × ''O. Glaberrima'' Steud. progenies in upland rice improvement|journal = [[Euphytica]] |date = 1997-03-01|issn = 0014-2336|pages = 237–246|volume = 94|issue = 2|doi = 10.1023/A:1002969932224|language = en|first1 = Monty P.|last1 = Jones|first2 = Michael|last2 = Dingkuhn|first3 = Gabriel K.|last3 = Alukosnm |first4 = Mandé|last4 = Semon|s2cid = 28577400}}</ref>

=== American cultivars ===
{{see also|Rice production in the United States}}
[[Carolina Gold]] is an heirloom cultivar grown in the early United States, sometimes known as golden-seed rice for the colour of its grains.<ref name=charleston>{{cite journal |url=http://www.carolinagoldricefoundation.org/papers/ricepaper.5.1.2011.pdf |title=Charleston Gold: A Direct Descendant of Carolina Gold |first=David S. |last=Shields |journal=[[The Rice Paper]]|volume=5 |issue=1 |year=2011|url-status=dead|archive-url=https://web.archive.org/web/20180513080911/http://www.carolinagoldricefoundation.org/papers/ricepaper.5.1.2011.pdf|archive-date=2018-05-13}}</ref>

Long-grain gold-seed rice boasted grains {{ Convert |5/12|in|mm}}inch long (up 11% from {{ Convert |3/8|in|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.<ref name=charleston/>

Charleston Gold was released in 2011 and is a crossbreed of Carolina Gold and two [[breeding line]]s of ''[[Oryza sativa var. indica|O. s. indica]]'' called {{ Visible anchor |IR64}}<ref>{{Cite book |doi=10.1385/1-59745-130-4:201 |issn=1064-3745 |volume=343 |pages=[https://archive.org/details/agrobacteriumpro00kanw/page/201 201–212] |last1=Datta |first1=Karabi |last2=Datta |first2=Swapan Kumar |chapter=Indica Rice (''Oryza sativa'', BR29 and IR64) |title=Agrobacterium Protocols |series= [[Methods in Molecular Biology]] |year=2006 |pmid=16988345 |isbn=978-1-59745-130-7 |chapter-url=https://archive.org/details/agrobacteriumpro00kanw/page/201 }}</ref> and {{ Visible anchor |IR65610-24-3-6-3-2-3}} (a [[dwarf rice|dwarf]], [[fragrant rice|fragrant]] breeding line), which raised the yield, shortened the stem, and added an aromatic quality to the rice.<ref name=charleston/> IR 64 Parboiled Rice 5% Broken is most famous and demanding rice in West African countries like Ghana, Togo, Benin etc.<ref>{{cite web |title=IR64 Parboiled Rice Exporters in India I Rice Master Global |url=https://ricemasterglobal.co.uk/ir64-parboiled-rice-exporters-in-india/ |website=Ricemasterglobal |date=18 May 2023}}</ref>

== References ==
{{ Reflist }}

== Further reading ==
*[https://web.archive.org/web/20071130210327/http://news.nationalgeographic.com/news/2007/11/071128-rice-origins_2.html Rice Origins 2] Slightly outdated [[National Geographic]] article on Carolina Gold (dead link 9 September 2019)
*{{Cite book| publisher = [[Douglas W. Bostick]] for the Carolina Gold Rice Foundation| isbn = 978-0-9829792-1-1| last1 = Shields| first1 = David S| author2-link = Carolina Gold Rice Foundation| last2 = Carolina Gold Rice Foundation| title = The golden seed: writings on the history and culture of Carolina gold rice| location = United States| date = 2010}}
*Fields-Black, Edda L. 2008. ''Deep Roots: Rice Farmers in West Africa and the African Diaspora''. (Blacks in the Diaspora.) [[Bloomington, Indiana|Bloomington]]: [[Indiana University Press]].

{{Rice}}
{{Taxonbar|from=Q2670252}}

[[Category:Oryza|glaberrima]]
[[Category:Grasses of Africa]]
[[Category:Flora of West Tropical Africa]]
[[Category:Rice]]
[[Category:Tropical agriculture]]
[[Category:Plants described in 1853]]
[[Category:Flora of Cameroon]]
[[Category:Flora of Chad]]
[[Category:Cereals]]