Phytopathology. 2006 Aug;96(8):867-75. doi: 10.1094/PHYTO-96-0867.
ABSTRACT Developing resistant cultivars requires an understanding of the dynamics of the pathogen populations as well as the genetics of host resistance. Bacterial leaf blight (BB), caused by the vascular pathogen Xanthomonas oryzae pv. oryzae, has become one of the most devastating diseases of rice. We demonstrate here the quantitative analyses of responses of near-isogenic lines carrying various BB resistance (R) genes and R-gene combinations against 16 X. oryzae pv. oryzae isolates representing Korean BB pathotypes. The estimated main effects of each R gene against the 16 isolates identified prominent differences in BB pathotypes between Korea and other countries. Three major aspects of our quantitative observations and statistical analysis are (i) strong and broad resistance of xa5; (ii) independent and additive genetic actions of Xa4, xa5, and Xa21 under digenic or trigenic status; and (iii) a strong quantitative complementation effect contributed by the functional alleles of Xa4 and Xa21. We conclude that the pyramid line containing genes Xa4, xa5, and Xa21 would be the most promising and valuable genotype for improving Korean japonica cultivars for BB resistance.
摘要 培育抗性品种需要了解病原体种群的动态以及宿主抗性的遗传学。由血管病原体稻黄单胞菌 pv.oryzae 引起的细菌性条斑病 (BB) 已成为水稻最具破坏性的疾病之一。我们在这里展示了对携带各种 BB 抗性 (R) 基因和 R 基因组合的近等基因系对代表韩国 BB 病原型的 16 个稻黄单胞菌 pv.oryzae 分离株的定量分析。对 16 个分离株的每个 R 基因的估计主效应确定了韩国和其他国家之间 BB 病原型之间的显著差异。我们的定量观察和统计分析的三个主要方面是：(i) xa5 的强而广泛的抗性；(ii) Xa4、xa5 和 Xa21 在双基因或三基因状态下的独立和累加遗传作用；以及 (iii) Xa4 和 Xa21 的功能等位基因贡献的强烈定量互补效应。我们得出结论，含有 Xa4、xa5 和 Xa21 基因的基因座将是改良韩国粳稻品种对 BB 抗性的最有前途和最有价值的基因型。
