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good resistance to iron toxicity, drought,nematodes, waterlogging, and majorAfrican rice diseases and pests. It seemsto adapt to acid soil with low phosphorusavailability.“Such multiple resistance toindigenous constraints is a highlydesirable character for rice cultivatedin the rainfed ecology in West Africaby resource-poor farmers, who cannotafford to adopt intensive agronomicmeasures against such constraints,” saidDr. Moussa Sié, senior rice breeder andcoordinator of the Rice Breeding TaskForce of AfricaRice.That is why AfricaRice scientistDr. Monty Jones and his team selectedCG 14 when they decided to cross O.glaberrima with O. sativa in the 1990sto develop productive rice varieties thatcan adapt to African conditions. Theysucceeded in breaking the natural barrierthat makes it difficult for the two speciesto cross. This was the genesis of the NewRice for Africa (NERICA). The bestNERICA varieties combine the stresstolerance of O. glaberrima with the highyield potential of O. sativa.“However, there are still gapsbetween the NERICA varieties andO. glaberrima in relation to resistanceto some local constraints,” Dr. KoichiFutakuchi, AfricaRice ecophysiologist,observes.AfricaRice therefore started tosystematically characterize its entire O.glaberrima collection of 2,500 samplesin 2009. A special effort is beingmade to screen for major diseases andenvironmental stresses such as acidity,iron toxicity, cold, and salinity.Explaining this comprehensiveeffort, Dr. Kayode Sanni, coordinator ofthe International Network for GeneticEvaluation of Rice for Africa (INGER-Africa), says that until now only a fewaccessions of O. glaberrima have beenused in the breeding programs.“By characterizing our O.glaberrima collection in our genebank,we may find new O. glaberrima lineswith better traits than the current parentallines of NERICA,” Dr. Sanni says.AfricaRice is also changing thebreeding concept as well as breedingprocedures to develop new interspecificvarieties. “The new concept forinterspecific breeding between O.AfricaRice upland ricebreeder Dr. Mandé Semonlooks at the new ricelines developed fromOryza glaberrima.glaberrima and O. sativa is to combinethe adaptability of O. glaberrima tolocal environments with the optimalconjunction of the best traits of the twospecies in relation to yielding ability,”says Dr. Futakuchi.Studies made by Dr. Futakuchiand his colleagues show that the O.glaberrima parent of the upland NERICAvarieties, CG 14, even produced morepanicles than the “panicle-numbertype” high-yielding O. sativa varieties,although its individual panicle wassmaller. The introduction of such anextraordinary trait may favor yieldingability.Such studies increasingly recognizethe “need to exploit the treasure trovethat is in African rice germplasm,” asAfricaRice upland rice breeder Dr.Mandé Semon puts it.Dr. Semon is leading the effort toobtain interspecific hybrids that haveBamakoDanyiplateauCentral and Western Africa.K. OROUmore O. glaberrima genes in the genomethan the current NERICA varieties,which were developed from backcrossingto an O. sativa parent. “We are usinginterspecific bridge lines in crosseswith O. glaberrima and O. barthii andno backcrossing has been done withthe O. sativa parent,” he explains. “Theprogenies will be ready for field testingsoon.”To better exploit the assets of O.glaberrima without being hampered bythe sterility problems of hybridizationwith another species, AfricaRicescientists have begun working on theintraspecific breeding of O. glaberrimaand are taking steps to develop plantsthat are less prone to lodging andshattering.Since O. glaberrima had beenconsidered to have generally low yieldpotential, interspecific hybridization withO. sativa, which has high yield potential,was a major method in using this species.However, AfricaRice breeders now thinkthat O. glaberrima can potentially yield5–6 tons per hectare, which is sufficientfor rainfed rice ecosystems in Africa.Initial results from crossing differenttypes of O. glaberrima also show thatcompletely different sets of genes areresponsible for tolerance of submergence,rice yellow mottle virus, and phosphorusdeficiency in soils from those in O.sativa.Some new products will likelybe derived using molecular breedingapproaches, through collaborative effortswith the International Rice ResearchInstitute and Chinese Academy ofAgricultural Sciences. AfricaRicescientists are already using this approachto introduce resistance to disease andother stresses into some of Africa’s mostpopular rice varieties.With Cornell University in theU.S., a single nucleotide polymorphism(SNP) chip is being developed basedon core collections of O. glaberrimaand O. barthii. This chip can efficientlyanalyze African germplasm and screeninterspecific progenies for desirabletraits.“We have new products in thepipeline for Africa’s rice farmers,particularly those who want to continueto grow African rice–like those of theDanyi plateau,” says Dr. Sié.Rice Today April-June 201033