【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JG30杂交,构建了包含2562个单株的F2作图群体。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的数据,筛选并合成12个EST标记的引物,进行亲本间多态性检测,找到2个在CBB23与JG30间有多态性的EST标记,C189和CP02662。用该标记对F2群体中的571个感病单株进行分子检测和连锁分析,结果表明这两个EST标记位于Xa23基因的两侧,C189靠着丝粒一侧,与Xa23的遗传距离为0.8cM;CP02662靠端粒一侧,与Xa23的遗传距离为1.3cM。将C189成功用于水稻分子育种实践,标记辅助选择的正确率接近100%,已培育出3个将Xa23基因与高产、优质、抗褐飞虱等性状聚合的水稻恢复系。更多还原

【Abstract】 A F2 population, with 2 562 individuals, of JG30/CBB23 was constructed for molecular mapping of the bacterial blight resistance gene Xa23 in rice. Inoculation test of the F2 plants showed that the segregation ratio of resistant and susceptible fits to 3:1. Based on the amthors previous mapping of Xa23 gene, 12 EST markers from Rice Genome Program (RGP) database were surveyed in the susceptible F2 plants and two markers, C189 and CP02662, were found flanking the Xa23 gene, with genetic distance of 0.8cM and 1.3cM, respectively. These two EST markers were successfully used in rice breeding program. The results showed that efficiency of C189 marker-assisted selection (MAS) for Xa23 gene was almost 100%. Three elite hybrid rice restore lines with Xa23 gene and improved bacterial blight resistance have been developed.更多还原