Accumulation of Salicylic Acid in Cucumber Treated with Glucohexaose and Its Relation to Systemic Acquired Resistance aga inst Cucumber Downy Mildew Effects of Glucohexaose on Sheath Blight,Pathogenesis-related Proteins and Endogenous Hormones in Flowering Chinese Cabbage Effects of Glucohexaose on Sheath Blight,Pathogenesis-related Proteins and Endogenous Hormones in Flowering Chinese Cabbage