Genetic Analysis on the Rice Blast and Brown planthopper Resistance of Namil(EMS)-bl10,bph1, a Japonica Rice Mutant Line

Rice is a source of food supply as the staple food.The narrow genetic diversity of Korean Japonica cultivars is prone to be susceptible to abiotic and biotic stresses such as rice blast, bacterial blight, and brown planthopper (BPH).The best approach for prevention of the breeding and extermination of disease and insect pest would be the development of rice cultivars harboring multiple disease and insect pest resistance genes.National Institute of Crop Science (NICS) in Korea developed a mutant line, Namil(EMS)-bl10,bph1, by using ethyl-methane-sulfonate (EMS) as the chemical mutagen on the wild type, Namil.The mutant line exhibits strong resistance levels against rice blast and brown planthopper.To localize favorable mutated allele types, two mapping populations were constructed by using F2 progenies derives crosses between Namil(EMS)-bl10,bph1 and Milyang23 and Namil (wild type) and Milyang23.Each F2 progenies were evaluated in terms of DNA marker genotype as well as agronomic traits measured, and for rice blast and BPH resistance, virulent blast isolate 94-254 and Korean biotype of BPH were used to screen F2:3 seedlings to conduct association analysis between marker genotype and evaluated phenotype of progeny lines.Through comparisons on major loci between two mapping populations, the putative major loci for rice blast resistance (RM1337, R 2 =54.4%) and BPH (RM0277, R 2 =55.1%) were primarily localized on chromosome 12.