International Rice Research Institute, Manila, Philippines.
Theor Appl Genet. 1978 May;53(3):105-11. doi: 10.1007/BF00272687.
The genetics of resistance to bacterial blight, Xanthomonas oryzae (Uyeda and Ishiyama) Dowson, for 74 cultivars of rice, Oryza sativa L., was studied. The PX061 isolate of bacterial blight from the Philippines was used for inoculation of parental and hybrid populations. Single dominant genes at the Xa 4 locus convey resistance in 38 cultivars. Of these, 18 are resistant at all stages of plant growth and thus have the Xa 4 (a)allele for resistance. However, 20 are susceptible up to maximum tillering stage but are resistant at booting and flowering stages. These cultivars have the Xa 4 (b)allele for resistance. Thirty-two cultivars have single recessive genes for resistance which are allelic to xa 5.The resistance in 'DV85', 'DV86' and 'DZ78' is conditioned by two genes. At maximum tillering stage xa 5 conveys resistance. However, at later growth stages an additional dominant gene, designated Xa 7 in 'DZ78', also gives resistance. The dominant genes of 'DV85' and 'DV86' are probably allelic to Xa 7. Xa 7 segregates independently of Xa 4, xa 5 and Xa 6, however like Xa 6, it conveys resistance at booting and post-booting stages only.The resistance in 'PI 231129' is conditioned by a single recessive gene, designated xa 8. It also segregates independently of Xa 4, xa 5 and Xa 6.
对 74 个水稻品种（Oryza sativa L.）的细菌性条斑病（Xanthomonas oryzae（Uyeda and Ishiyama）Dowson）抗性的遗传进行了研究。菲律宾的 PX061 分离物用于接种亲本和杂种群体。38 个品种在 Xa4 基因座上的单个显性基因赋予抗性。其中，18 个在植物生长的各个阶段都具有抗性，因此具有 Xa4(a)等位基因的抗性。然而，20 个在最大分蘖阶段易感，但在抽穗和开花阶段具有抗性。这些品种具有 Xa4(b)等位基因的抗性。32 个品种具有单一隐性基因抗性，这些基因与 xa5 等位。‘DV85’、‘DV86’和‘DZ78’的抗性由两个基因决定。在最大分蘖阶段，xa5 赋予抗性。然而，在后期生长阶段，一个额外的显性基因，在‘DZ78’中被命名为 Xa7，也赋予抗性。‘DV85’和‘DV86’的显性基因可能与 Xa7 等位。Xa7 独立于 Xa4、xa5 和 Xa6 分离，但与 Xa6 一样，仅在抽穗和抽穗后阶段赋予抗性。‘PI 231129’的抗性由一个单一的隐性基因，命名为 xa8，决定。它也独立于 Xa4、xa5 和 Xa6 分离。
