利用广谱抗稻瘟病基因Pi9基因序列设计的特异分子标记Pi9–a,通过回交育种和分子标记辅助选择技术,改良8份受体水稻材料(丰源B、Ⅱ32B、天龙香103、香丰187、明恢63、轮回422、R747、25H003)的稻瘟病抗性。结果表明:分子标记Pi9–a对8份受体亲本与Pi9供体亲本75–1–127间进行的多态性检测中,除香丰187外,其余7个组合间均存在稳定明显的多态;对4个BC1F1群体进行随机取样的基因型和表型鉴定中,Pi9–a对抗稻瘟病表型选择的效率均为100%。 Eight rice varieties (Fengyuan B, Ⅱ32B, Tianlongxiang 103, Xiangfeng) were modified by backcross breeding and molecular marker-assisted selection using the specific molecular marker Pi9-a designed by the broad-spectrum blast resistance Pi9 gene sequence. 187, Minghui 63, Rei 422, R747, 25H003). The results showed that the marker Pi9-a was significantly and stably amplified except for Xiangfeng 187 among the seven combinations of 8 recipient and Pi9 donor parents, 75-1-127 The genotypes and phenotypes of four BC1F1 populations were randomly selected. The efficiency of Pi9-a for blast phenotype selection was 100%.