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稻白叶枯病(bacterial blight,BB)是威胁中国水稻生产的最主要病害之一.本研究在田间观察材料时发现普通野生稻染色体片段代换系CSSL45高感白叶枯病,于是利用6个不同的白叶枯菌株对CSSL45及其受体亲本9311进行抗性鉴定,结果表明它们之间对不同菌株表现出明显的抗感病差异.随后利用GX0312菌株对9311/CSSL45的194个F2分离单株进行接种鉴定,遗传分析表明:籼稻品种9311的抗性由一个显性的抗白叶枯基因控制.最后进一步利用分子标记对472株感白叶枯病的单株进行重组单株检测,最终将Xa41(t)定位在水稻第1 1号染色体的SSR标记RM27320和RM27335之间,物理距离约为220kb.本研究定位的Xa41(t)可能与此前报道的4个抗性基因Xa3/Xa26、Xa4和Xa40是互为等位基因.因此,合理利用Xa41(t)基因与其他不同抗性基因进行聚合,对广西水稻白叶枯病抗性育种具有重要的意义.“,”Bacterial blight is one of the most serious diseases to rice production in china.In this study,it was found common wild rice chromosome segment substitution line CSSL45 was highly susceptible to bacterial blight in field.Subsequently,the CSSL45 and recipient parent 9311 were inoculated with 6 different Xoo strains,and the results indicated that they showed distinct resistance difference among different strains.Then,Xoo strain GX0312 were used for evaluating the resistance of 194 F2 plants of 9311/CSSL45,and the genetic analysis indicated that the resistance of indica CV.9311 was controlled by a dominant resistance gene.Finally,the molecular markers were used to detect the recombinants of 472 susceptible plants,and the Xa41 (t) was located between SSR markers RM27320 and RM27335 on chromosome 11,with a physical distance of about 220 kb.The Xa41(t) identified in this study might be the allele of other 4 previously reported resistance genes Xa3/Xa26,Xa4 and Xa40.Therefore,it was useful to Xa41(t) for pyramiding with other resistance genes for rice bacterial blight resistance breeding in Guangxi.