Evaluation of rice genotypes resistance to bacterial leaf blight in Togo

The present study aimed to evaluate rice genotypes for resistance to bacterial leaf blight caused by Xanthomonas oryzae pv. oryzae. Twenty-one genotypes including six genotypes grown in Togo, two improved genotypes from Africa Rice and thirteen isogenic lines from IRRI were tested. The results revealed differential reactions of genotypes in the expression of the disease. Additive main effect and multiplicative interaction analysis allowed identifying three groups of genotypes according to the level of the disease expression: resistant group made up of the genotype IR24 and all the twelve near isogenic lines tested except the line IRBB5, medium resistant group made up of three genotypes grown in Togo (NERICA4, NERICA8 and NERICA14), the genotype Giganté from AfricaRice, and susceptible group including five genotypes from ITRA (TGR203 and IR841), from AfricaRice (NERICA19 and TOG5681) and the near isogenic line IRBB5 from IRRI. The results provided useful information indicating that none of the grown varieties tested was resistant to BLB, thus revealing a potential risk of epidemics since these genotypes were only medium resistant to susceptible. However, experiments under field conditions in different environments of Togo are needed