Abstract: Using Artemisia frigida and Artemisia scoparia as root stocks, grafted chrysanthemum were created. The membrane permeability, O^-·2 p roduction rate, and activities of superoxide dismutase ( SOD ) , peroxidase ( POD) , catalase (CAT) , ascrobate peroxidase (APX) and contents of soluble p rotein in leaves of the cutting seedlings and grafted seedlings of chrysanthemum were studied under heat stress. The results showed that grafted seedlings had lowermembrane permeability and O₂^-· production rate, while SOD, CAT and
APX activities and soluble p rotein contentswere higher compared with those in the cutting seedlings. However, there was no significant difference in O₂^-·production rate and activities of antioxidant enzymes between the grafted seedlingswith different root stocks. The leaf curling, wilting, yellowingwere alleviated in grafted seedling than those in cutting seedlings under heat stress. It suggested that grafting could imp rove the heat tolerance of chrysanthemum.

Key words: heattolerance, chrysanthemum, grafted, antioxidant enzymes activities