Oryza glaberrima:: A source for the improvement of Oryza sativa

African rice Oryza glaberrima (2n = 24, AA) has many unique traits such as weed competitiveness, drought tolerance and the ability to grow under low input conditions. These traits have been recently combined with high yield of Oryza sativa to develop NERICA (NEw RIce for AfriCA). The new rice varieties are high-yielding, drought- and pest-resistant and are uniquely adapted to the growing conditions of West Africa. The major problems in combining useful traits of both cultivated Oryza species are sexual incompatibility and hybrid sterility. Reproductive barriers between the two species have been studied and genetic models based on sporo-gametophytic interactions proposed. The availability of a molecular linkage map of O. glaberrima and molecular markers linked to sterility loci would aid in the introgression of desirable traits and elimination of sterility loci quickly. The use of O. glaberrima in rice breeding is challenging, but promising. The genetic base of Asian rice O. sativa can be widened for obtaining higher yields under adverse conditions and using non-transgenic approaches.