Evolution of the African Rice: A Historical and Biological Perspective

Abstract

The usual assumption is that African rice {Oryza glaberrima Sfeud.) originated about 3500 yr ago from fhe annual wild rice, Oryza barthii A. Chev., and Asian rice {Oryza sativa L.) was introduced info West Africa in fhe lafe 15fh century CE) by the Europeans. Evidences from several social science and biological science disciplines have been collated and/or reinferpreted to draw the following inferences: (i) There are several accounts of rice culture in northern and western Africa from early centuries of the Common Era; (ii) The Senegamblan monoliths, linked to the fime of origin of African rice as 3500 yr ago, have been carbon dafed fo the 7th century CE; (iii) Neolithic culture had hardly reached tropical West Africa 3500 yr ago; (iv) The characteristics of O. barthii vis-à-vis the two cultivated rices-bigger grains, higher yields, easy crossability with both intermediate features, and weediness-may suggest its hybrid nature; and (v) The rarity of O. glaberrima beginning with the time of its initial identification, acceptance of local farmers to having both rices growing together, repeated discovery of O. glaberrima-Wke forms in non-African rice regions, and prevalence of close colinearify between the two cultivated rices at molecular and chromosomal levels suggest their close relationships. These factors indicate that African rice might have evolved from Asian rice, and that the wild rice, O. barthii, might be a hybrid derivative of the two cultivated rices.

Genetically Characterizing a New Indica Cytoplasmic Male Sterility with Oryza glaberrima Cytoplasm for Its Potential Use in Hybrid Rice Production

“…The regenerated F 1 plants flowered in the short-photoperiod environment of the tropics, but all of them were male sterile. As noted by previous breeders, there is a high percentage of sterility in the interspecific F 1 hybrids between O. glaberrima and O. sativa irrespective of the combinations of parental lines (Jones, 1999;Sarla and Mallikarjuna Swamy, 2005;Efisue et al, 2008;Nayar, 2012). To develop introgression lines and new CMS lines, multiple crosses and backcrosses were made using the sterile F 1 as female parents and indica cultivars of O. sativa as male parents.…”

Revue analytique des performances agronomiques, nutritionnelles et perspectives de valorisation du riz africain (<i>Oryza glaberrima</i>)

“…Bien qu'en constante déclin, sa production est localisée au nord dans le Sud-Ouest de la Mauritanie et le centre du Mali, et au sud sur toute la côte du Golfe de Guinée. La zone de production du riz africain s'étend par ailleurs de la côte sénégalaise jusqu'au Sud-Ouest du Tchad (Nayar, 2012).Les systèmes de riziculture ouest africains sont d'une grande diversité. Le riz de mangrove et de basfonds prédominent dans les zones côtières le long du golfe de Guinée, tandis que le riz pluvial est cultivé dans des zones de plateaux comme en Guinée, dans le Sud du Mali, dans l'Ouest du Benin et au Nigeria.…”

“…De nos jours, le riz africain est rarement cultivé en culture pure. Il est souvent associé au riz asiatique qui est de plus en plus dominante sur le continent (Nayar, 2012). Potentialités génétiques du riz africain : Oryza glaberrima est une espèce qui renferme des ressources génétiques encore inexploitées (Pham, 1992) qui pourraient être utilisées, pour l'instant, à l'intensification de certains types de riziculture, tels que la riziculture de bas-fonds.…”

Comparison between wild and related cultivated rice species reveals strong impacts of crop domestication on methane metabolism of the rhizomicrobiome

“…The development of cultivated rice from wild rice signi cantly altered desired traits, such as it increased yields and nutrient contents [4,5]. African and Asian cultivated rice species were differently domesticated [6][7][8]. African cultivated rice, O. glaberrima, was domesticated from African wild rice, O. barthii, while Asian cultivated rice, O. sativa, was domesticated from common wild rice (O. ru pogon) or nivara wild rice (O. nivara) [9][10][11].…”