【摘要】 用水稻抗白叶枯病基因Xa23的近等基因系CBB23与其感病轮回亲本金刚30(JG30)杂交,构建了包含2562个单株的F2作图群体。用水稻白叶枯病广致病菌系P6进行抗性鉴定表明,F2植株抗感分离比严格符合3∶1。根据日本水稻基因组计划RGP水稻高密度图谱上的RFLP探针对F2群体中的145个感病单株进行RFLP检测和连锁分析,获得了6个与Xa23紧密连锁的RFLP分子标记。其中RFLP标记C1003A靠着丝粒一侧,与Xa23的遗传图距为0.4 cM,为Xa23的图位克隆奠定了重要基础。并将标记C1003A成功地转化为STS标记,为分子标记辅助选择育种(MAS)提供了方便有效的分子标记。更多还原

【Abstract】 A F₂ population derived from cross of the Xa23 near isogenic lines,JG30 and CBB23,was used for fine mapping of the rice bacterial blight resistance gene Xa23.Inoculation of the F₂ plants with a Xanthomonas oryzae strain P6 showed a 3:1 ratio for the segregation of resistant and susceptible as expected.One hundred and forty-five susceptible plants were selected from the F₂ population for mapping the gene Xa23 and fifteen restriction fragment length polymorphism（RFLP） markers anchored on the rice high-density map. A RFLP marker C1003A was found to be linked to the gene Xa23 by 0.4 cM.This result constitutes an important basis for map-based cloning of the gene Xa23.The RFLP marker C1003A was transformed into sequence-tagged-site（STS） marker,which can be applied for molecular marker-assisted selection（MAS） of Xa23 in rice breeding programs.更多还原