水稻品种大粒香以米质优、香味浓郁连续5次获“中国优质稻米博览交易会金奖”，但因高感稻瘟病，严重限制了其在生产上的应用。本研究以含有广谱抗性基因Pi9的空育131为父本，通过常规杂交、连续回交和分子标记辅助选择将Pi9导入大粒香中，创制株叶形态、千粒重、米质及香味等重要性状上与大粒香基本一致的改良株系。大粒香改良株系抗性鉴定结果表明，其稻瘟病抗性与大粒香相比显著提升，达到品种生产应用的抗性标准，实现对大粒香稻瘟病抗性的定向改良。

Dalixiang has won the “China Rice Expo Gold Award” for its excellent rice quality and rich aroma for five consecutive times. However, its high susceptibility to rice blast severely limits its large-scale application in production. Using the male parent of Kongyu 131 containing the broad-spectrum resistance gene Pi9, through conventional hybridization, continuous backcrossing, and molecular marker-assisted selection, we introduced Pi9 gene into Dalixiang. An improved strain was created, which had important traits such as leaf morphology, thousand grain weight, rice quality, and aroma that were basically consistent with Dalixiang. The identification results of the resistance of the improved strain of Dalixiang showed that its blast resistance was significantly improved compared to Dalixiang, meeting the resistance standards for variety production and application, achieving directional improvement of blast resistance in Dalixiang.