Abstract: The inheritance and gene effects for resistance to bacterial blight Xanthomonas oryzae pv. oryzae in four rice varieties were analyzed by bi-parental backcrossing design. The inheritance of resistance to two strains (typeⅡ: KS-6-6 & type Ⅳ: Zhe 173) was found to be incompletely recessive, which was in good conformity with the additive-dominance model by the individual scaling test; additive effects were highly significant but not the dominance and epistatic effects. The additive genetic variation contributes most to the total although both additive and dominance variations were present, as were shown by the higher heritabilities in both broad sense and narrow sense. A highly significant positive correlation found between the disease scores of strains (Ⅱ and Ⅳ ) indicated that they are non-independently inheritant. It was inferred that the resistance to both strains of bacterial blight in the resistant variety, Jia 23, is characteristic of quantitative inheritance of incomplete recessiveness which may be controlled by a set of multiple genes, and at least one pair of recessive genes in terms of the effective factors is shown to play the leading role in the varieties studied. Implication of screening and selective breeding of resistant rice lines was also discussed.

Key words: bacterial blight, gene effects, inheritance, resistance, pathogenic strain

摘要： 以4个晚粳品种为材料，采用双亲本回交设计对白叶枯病抗性的遗传特性及基因效应作了分析。参试的晚粳品种对两个菌系KS-6-6和浙173的抗性是不完全隐性遗传，符合加性－显性模型；基因的加性效应为极显著，显性效应和上位性效应则皆不显著。加性变异和显性变异并存，但以加性遗传变异为主，表现具有较高的广义、狭义遗传率。菌系Ⅱ与Ⅳ的病级间的关联性表明，晚粳品种嘉23对白叶枯病两菌系的抗性属同一多基因系控制的不完全隐性的数量性状遗传；从有效因子数目估值来看，本研究参试材料至少有一对隐性抗病基因在起作用。

关键词: 白叶枯病, 菌系, 抗性, 遗传, 基因效应