Hunan Agricultural University, Changsha, China.
Phytopathology. 2011 May;101(5):620-6. doi: 10.1094/PHYTO-08-10-0209.
The indica rice cultivar Xiangzi 3150 (XZ3150) confers a high level of resistance to 95% of the isolates of Magnaporthe oryzae (the agent of rice blast disease) collected in Hunan Province, China. To identify the resistance (R) gene(s) controlling the high level of resistance in this cultivar, we developed 286 F(9) recombinant inbred lines (RILs) from a cross between XZ3150 and the highly susceptible cultivar CO39. Inoculation of the RILs and an F(2) population from a cross between the two cultivars with the avirulent isolate 193-1-1 in the growth chamber indicated the presence of two dominant R genes in XZ3150. A linkage map with 134 polymorphic simple sequence repeat and single feature polymorphism markers was constructed with the genotype data of the 286 RILs. Composite interval mapping (CIM) using the results of 193-1-1 inoculation showed that two major R genes, designated Pi47 and Pi48, were located between RM206 and RM224 on chromosome 11, and between RM5364 and RM7102 on chromosome 12, respectively. Interestingly, the CIM analysis of the four resistant components of the RILs to the field blast population revealed that Pi47 and Pi48 were also the major genetic factors responsible for the field resistance in XZ3150. The DNA markers linked to the new R genes identified in this study should be useful for further fine mapping, gene cloning, and marker-aided breeding of blast-resistant rice cultivars.
籼稻品种 Xiangzi 3150（XZ3150）对在中国湖南省收集的 95%的稻瘟病菌（稻瘟病的病原体）分离物具有高水平的抗性。为了鉴定该品种中控制高水平抗性的抗性（R）基因（s），我们用 XZ3150 与高感品种 CO39 杂交，开发了 286 个 F(9)重组自交系（RILs）。在温室中用无毒分离物 193-1-1 接种 RILs 和两个品种的 F(2)群体表明，XZ3150 中存在两个显性 R 基因。用 286 个 RILs 的基因型数据构建了一个包含 134 个多态性简单序列重复和单特征多态性标记的连锁图谱。使用 193-1-1 接种结果的复合区间作图（CIM）表明，两个主要的 R 基因，分别命名为 Pi47 和 Pi48，位于第 11 号染色体上的 RM206 和 RM224 之间，以及第 12 号染色体上的 RM5364 和 RM7102 之间。有趣的是，对 RILs 对田间流行种群的四个抗性成分的 CIM 分析表明，Pi47 和 Pi48 也是 XZ3150 田间抗性的主要遗传因素。本研究中鉴定的新 R 基因的 DNA 标记应有助于进一步进行精细作图、基因克隆和抗稻瘟病水稻品种的标记辅助选择。
