Abstract:

【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.