Abstract: Using rice lines C101LAC and C101A51 as the donors of the resistance genes to rice blast, three resistance genes (Pi1, Pi2 and Pi33) were introgressed into an elite variety Jin 23B by crossing, backcrossing and multicrossing. Six nearisogenic lines of Jin 23B with the three resistance genes were obtained through traditional breeding method combined with markerassisted selection method, and the resistance frequency was 96.7%. The results indicated that the resistance frequency of the lines with the three resistance genes were higher than that of single resistance gene line. It could be concluded that gene pyramiding is an effective approach for the improvement of rice varieties with durable resistance to rice blast.

Key words: rice, rice blast, resistance gene, marker assisted selection

摘要： 以C101LAC和C101A51为稻瘟病抗性基因的供体亲本，金23B为受体亲本，通过杂交、复交及一次回交，在分离世代，利用分子标记辅助选择技术结合特异稻瘟病菌株接种鉴定和农艺性状筛选，获得6个导入Pi1、Pi2和Pi33基因的金23B导入系，其中导入系W1对稻瘟病的抗病频率为96.7%，明显高于携带单个基因的C104LAC（Pi1）、C101A51（Pi2）和北京糯（Pi33）。基因聚合后抗病频率提高，说明基因聚合是培育稻瘟病持久抗性的有效方法之一。

关键词: 水稻, 稻瘟病, 抗病基因, 分子标记辅助选择