Abstract: Resistance identifications of pib gene were performed with 36 rice blast fungus strains Collected from Sichuan. Meanwhile the dominant molecular markers of the rice blast resistance gene pib were used to identify the presence in the pib gene of 122 hybrid parents and materials. Pathogenicity assays were performed with the rice blast fungus strains ZB13 and ZC15 with artificial inoculation. The results indicated that pib was a gene of high resistance with a relatively great difference of resistance in different materials. Only 7 of the 122 hybrid parents and materials contained the resistance gene and showed resistance to rice blast fungus strains ZB13 and ZC15. In addition, two pairs of dominant markers Pibdom and Lys145 were used to screen the 6 F2 populations at the early stage. 185 plants of 600 F2 plants containing homozygous pib gene were isolated. At the same time, the rice blast resistances of these plants in the field were investigated. The results demonstrated that the presence of resistance gene consisted with the resistance in the field. Therefore, the set of dominant markers are useful for marker-assisted selection of the rice blast resistance gene pib.

Key words: Rice (Oryza sativa L.), Rice blast resistance Pib gene, Molecular markers, Marker-assisted selection