Abstract: By using 20 F₂ segregating populations derived from the crosses between Fengqing 2, a Yunnan variety resistant to bacterial blight, and 14 japonica marker stocks and 6 primary trisomics, the linkage genetic analysis shows that Fengqing 2 has a gene Xa-j which confers resistance to bacterial blight(Xanthomonas campestris pv. oryzae) strain Jiangling 691 from Hubei Province of China. The gene Xa-j is linked to the marker gene sp of linkage group Ⅷ with map distance of 23. 2% and has a close relationship with primary trisomics G which has extra chromosome 9. Therefore, the gene Xa-j is located on chromosome 9.

Key words: Xanthomonas campestris pv.oryzae, Gene location: Primary trisomics, Marker gene

摘要： 风情2号与14个水稻粳型标记系及6个初级三体所配组合的F₂群体的遗传分析表明：风情2号对我国湖北省的白叶枯病菌江陵691的抗性是由一对显性抗病基因Xa-j控制的；Xa-j与所用的25个标记基因中的短穗基因sp连锁，重组值为23.2%，属于第Ⅷ 连锁群；三体分析推断出Xa-j与三体G(KTG)的额外染色体(即第9染色体)有关，与连锁分析的结果相印证。抗病基因Xa-j被定位于第9染色体上。

关键词: 水稻, 白叶枯病, 抗病性, 基因定位, 初级三体