【研究目的】茉莉酸在小麦（Triticum aestivum L.）抗白粉病反应中是否起作用及其作用强度仍不清楚，为了明确茉莉酸对小麦白粉病抗性的诱导作用进行了本研究。【方法】以感白粉病的小麦品种“中国春”和“濮麦9号”为材料，用不同浓度的茉莉酸甲酯喷施小麦幼苗叶片进行诱导，通过离体叶段培养法接种白粉菌（Blumeria graminis f. sp. tritici，Bgt）进行抗性鉴定。【结果】结果表明，茉莉酸甲酯处理可以提高“中国春”和“濮麦9号”对白粉菌的抗性水平，抗性提高与诱导的茉莉酸甲酯浓度和诱导时间有关。浓度为100 μmol/L、250 μmol/L时诱导抗性不明显，500 μmol/L时有明显的诱导抗性，1.0 mmol/L以上具有显著的诱导效果。茉莉酸甲酯处理后12 h至96 h后均可检测到诱导抗性，而以诱导24 h后诱导抗性最高。【结论】实验表明植物激素茉莉酸在小麦抗白粉病反应中起作用，是抗病信号分子。

【Objective】It is unclear that whether jasmonic acid is a signal molecule for wheat (Triticum aestivum L.) powdery mildew resistance and how high the resistance can be induced. To address these problems, a study was done here. 【Method】Powdery mildew susceptible cultivars “Chinese Spring” and “Pumai 9” were used to study wheat powdery mildew resistance activated by methyl jasmonate (MeJA). The reaction types of powdery mildew were evaluated by detached leaf assay. 【Result】The results showed that MeJA application increased the powdery mildew resistances of “Chinese Spring” and “Pumai 9”. The powdery mildew resistance was associated with the concentration of MeJA and the interval between MeJA spraying and inoculation with Blumeria graminis f. sp. tritici. The activated powdery mildew resistance was undetectable when induced with MeJA of 100 μmol/L or 250 μmol/L, but it could be detected when the concentration reached to 500 μmol/L, and the resistance was significantly induced when above 1.0 mmol/L. The induced powdery mildew resistance could be detected from 12 h to 96 h after MeJA spraying, and the top value was at 24 h. 【Conclusion】This study indicated that phytohormone JA was a signal molecule in wheat powdery mildew resistance reaction.