Seed dormancy is a major limiting factor for the conservation, evaluation, distribution and utilization of African cultivated rice (Oryza glaberrima). In this study, 20 accessions from the AfricaRice genebank were subjected to different treatments: dry heat at 50 or 60°C for 2 to 28 days; chemical solutions (KCl, HNO3, KH2PO4, GA3); and dehulling...
Utilizing the full potential of rice collections mainly depends on an in-depth exploration and understanding of the vast diversity in its germplasm. The AfricaRice genebank holds the largest collection of rice germplasm originating from the African continent. In the present study, we comprehensively characterized a collection of 9013 accessions, including Oryza barthii A. Chev., Oryza glaberrima Steud., Oryza...
There is a recent unparalleled increase in demand for rice in sub-Saharan Africa, yet its production is affected by blast disease. Characterization of blast resistance in adapted African rice cultivars can provide important information to guide growers and rice breeders...
African cultivated rice (Oryza glaberrima Steud.) was domesticated from its wild progenitor species (Oryza barthii) about 3000 years ago. Seed shattering is one of the main constraints on grain production in African cultivated rice, which causes severe grain losses during harvest...
Rice yellow mottle virus (RYMV) is a major biotic constraint to rice cultivation in Africa. RYMV shows a high genetic diversity. Viral lineages were defined according to the coat protein (CP) phylogeny. Varietal selection is considered as the most efficient way to manage RYMV...
African cultivated rice, Oryza glaberrima, is characterized by its glabrous glumes. During domestication, the pubescent glumes of its wild ancestor, Oryza barthii, lost their trichomes, and in this study, we show that glabrous glume 5 (GLAG5)...
African rice (Oryza glaberrima Steud) is one of the two independently domesticated rice species, the other one being Asian rice (Oryza sativa L.). Despite major progress being made in understanding the evolutionary and domestication history of African rice...
Genebanks underpin global food security, conserving and distributing agrobiodiversity for use in research and breeding. The CGIAR collections include >700,000 seed accessions, held in trust as global public goods...
African rice (Oryza glaberrima Steud) is one of the two independently domesticated rice species, the other one being Asian rice (Oryza sativa L.). Despite major progress being made in understanding the evolutionary and domestication history of African rice...
Previous studies conducted on limited number of accessions have reported very low genetic variation in African rice (Oryza glaberrima Steud.) as compared to its wild progenitor (O. barthii A. Chev.) and to Asian rice (O. sativa L.)...
To minimize the cost of sample preparation and genotyping, most genebank genomics studies in self-pollinating species are conducted on a single individual to represent an accession, which may be heterogeneous with...
The international collections of plant genetic resources for food and agriculture (PGRFA) hosted by 11 CGIAR Centers are important components of the United Nations Food and Agriculture Organization’s global system of conservation and use of PGRFA...
African rice (Oryza glaberrima) has a pool of genes for resistance to diverse biotic and abiotic stresses, making it an important genetic resource for rice improvement. African rice has potential for breeding for climate resilience and adapting rice cultivation to climate change....
Species misclassification (misidentification) and handling errors have been frequently reported in various plant species conserved at diverse gene banks, which could restrict use of germplasm for correct purpose. The objectives of the present study were to (i) determine the extent of...
Morphological identification of closely related rice species, particularly those in the Oryza AA genome group, presents major challenges and often results in cases of misidentification. Recent work by this group identified diagnostic single nucleotide polymorphic (SNP) markers specific for...
Drought is a major constraint to rice (Oryza spp.) production in sub-Saharan Africa. Oryza glaberrima Steud., the cultivated rice species that originated from West Africa, is well-adapted to its growing ecologies. This study was initiated to identify...
Global efforts have seen the world’s plant genetic resources (PGRs) conserved in about 1625 germ plasm repositories. Utility of these resources is important in increasing the resilience and productivity of agricultural production systems...
African rice (Oryza glaberrima) was domesticated independently from Asian rice. The geographical origin of its domestication remains elusive. Using 246 new whole-genome sequences, we inferred the cradle of its...
Using interspecific crosses involving Oryza glaberrima Steud. as donor and O. sativa L. as recurrent parents, rice breeders at the Africa Rice Center developed several ‘New Rice for Africa (NERICA)’ improved varieties...
The sequence variation present in accessions conserved in genebanks can best be used in plant improvement when it is properly characterized and published. Using low cost and high density single nucleotide polymorphism (SNP) assays, the genetic diversity, population structure, and...
Amylose content (AC) is a key quality trait in rice. A cross between Oryza glaberrima (African rice) and Oryza sativa (Asian rice) segregating for AC was analysed by sequencing bulks of individuals with high and low AC. SNP associated with...
Oryza glaberrima is one of the two cultivated species of rice, and harbors various interesting agronomic traits, especially in biotic and abiotic resistance, compared with its Asian cousin O. sativa. A previous reference genome was published but...
Rice genetic resources conservation and evaluation is crucial to ensure germplasm sources for further crop breeding. We conducted a wide collection of Oryza species in Niger and characterize its...
The study evaluated effects of drought on some agro-morphological traits of 60 rice genotypes comprising 54 introgression lines with their parents, IR 64 (Oryza sativa) and TOG 5681 (Oryza glaberrima) and four NERICA-L varieties...
African rice (Oryza glaberrima) was neglected for a long time by researchers but gained attention with the success of NERICA varieties. While AfricaRice holds a collection of about 2,500 O. glaberrima samples only four...
Xanthomonas oryzae pv. oryzae is the causal agent of bacterial blight in rice, one of the most devastating diseases of rice worldwide. African X. oryzae pv. oryzae strains belong to a clear genetic group distinct from those of Asia. Three new races of the pathogen were...
Rice yellow mottle virus (RYMV) is the most damaging rice-infecting virus in Africa. However, few sources of high resistance and only a single major resistance gene, RYMV1, are known to date...
The ability to identify drought-resistant lines in all seasons would accelerate variety introduction. A total of 202 backcross-inbred lines of rice were subjected to drought during the 2006 and 2007 dry seasons at...
We report here evidence of the role that the isoform of the eukaryotic translation initiation factor 4G (eIF(iso)4G) plays in naturally occurring resistance in plant/virus interactions. A genetic and physical mapping approach was...
Identification and differentiation of three Nigerian Orseolia sp. (Orseolia nwanzei, Orseolia bonzii and Orseolia oryzivora) was carried out using Random Amplified Polymorphic DNA (RAPD) markers. Ninety operon primers were screened, from which 6 showed polymorphism among the three species tested, generating 54 bands, 69% of...
The genetic relationship and distance among rice varieties widely being used as parents by the African Rice Center (WARDA) are largely unknown but of great interest for breeding programs. The genetic relationship among 16 rice varieties was investigated using 83 EST and 174 SSR markers.
Marker assisted backcrossing (MAB) is one of the most anticipated and frequently cited benefits of molecular markers as indirect selection tools in breeding programs. However, routine implementations of MAB in ongoing plant breeding...
The development and use of molecular markers for the detection and exploitation of DNA polymorphism is one of the most significant developments in the field of molecular genetics. The presence of various types of molecular markers, and differences in...
Genetic mapping (also known as linkage mapping or meiotic mapping) refers to the determination of the relative position and distances between markers along chromosomes. Genetic map distances between two markers are defined as the...
The Africa Rice Center (WARDA) has developed several interspecific rice varieties by crossing the high yielding Asian rice (Oryza sativa subsp. japonica) with the locally adapted African rice (Oryza glaberrima). Eighteen varieties were named with the prefix NERICA (New Rice for Africa) but...
The very high resistance to Rice yellow mottle virus observed in the two rice varieties Gigante (Oryza sativa) and Tog 5681 (O. glaberrima) is monogenic and recessive. Bulked segregant analysis was carried out to identify AFLP markers linked to the resistance gene...
Rice yellow mottle virus (RYMV) accumulation in protoplasts and whole plants was investigated in two highly resistant cultivars, Tog5681 (Oryza glaberrima) and Gigante (Oryza sativa). Three susceptible cultivars, i.e. one O. glaberrima Tog5673 and...
Oryza glaberrima is an endemic African cultivated rice species. To provide a tool for evaluation and utilisation of the potential of O. glaberrima in rice breeding, we developed an interspecific O. glaberrima×Oryza sativa genetic linkage map. It was based on PCR markers...
Three cultivars of Oryza sativa (IR64, Azucena, and Gigante) and four cultivars of O. glaberrima (Tog5681, Tog5673, CG14, and SG329) were evaluated for their resistance to two isolates of rice yellow mottle virus (RYMV) by enzyme-linked immunosorbent assay (ELISA) and symptomatology...
