Abstract: By means of Cumulative Distribution Curve Method, seven sets of F₃ lines derived from the cross combination (Norin 20 × Dengnong 415) were tested with seven Japanese strains of Pyricularia grisea Saccardo. The results indicated that the resistance of Dongnong 415 to P2b, Hoku 1, Ina 168 strains was controlled by three dominant genes, and the resistance to Ina 72 and Ken 54-20 strains was controlled by two dominant genes; to Ken 53-33 strain by two complementary dominant genes; to Ken 54-04 strain by two dominant genes and one recessive gene. Accordingly, there were at least three dominant genes for blast resistance in rice variety, Dengnong 415, and there were interactions between these genes.

Key words: cumulative distribution curve method, fungus strain, resistance gene, Pyricularia grisea

摘要： 采用“累积分布曲线法”用日本7个单基因鉴别菌系(P-2b、研53-33、稻72、北1、研54-20、研54-04、稻168)接种鉴定了农林20×东农415组合7套F3系统。结果表明，东农415对P-2b、北1、稻168三个菌系的抗性是由三对显性基因控制的；对研53-33菌系是由两对显性互补基因控制的；对研54-04菌系的抗性是由两对显性基因和一对隐性基因控制的；对稻72和研54-20两个菌系的抗性是由两对显性基因控制的。分析结果显示水稻品种东农415至少含有三个显性抗瘟性基因，且基因间存在互作。

关键词: 稻瘟病, 菌系, 抗性基因, 累积分布曲线法