Abstract: The physiological responses of tea p lants to aluminum (Al) and fluorine ( F) interaction stressing were studied, and six physiological indices were investigated in tow varieties Baicha and Zhirenzaocha at 30 d, including the membrane permeability of leaf cells (MP) , the root system activity (RA) , free proline (Pro) content, the activity of catalase (CAT) , peroxidase ( POD) and superoxidedismutase ( SOD). Tea plants was cultured in nutrient solution which contained Al (0, 30, 90 mg·L ^-1) and /or F (0, 4, 12 mg·L ^-1). The results were summarized as follows: (1) RA in roots and the activity of SOD in leaves were enhanced with 30 mg·L^-1 of Al alone, but MP and activity of POD and CAT in leaves declined; (2) When the concentration of F alone was 4 mg·L ^-1 and 12 mg·L ^-1, enzymes of tea leaves increased andMP and RA in roots decrease compared with control (0 mg·L ^-1 Al and 0 mg·L ^-1F) ; (3) RA, content of Pro and the activity of POD, CAT and SOD were lower under high Al and low F interaction compared with 90 mg·L ^-1 Al alone. Maybe Al and F cooperated with each other during growth of tea plants. When proportion of Al and F were from 30 /4 to 30 /12, activity of POD, CAT and SOD showed an obvious upward tendency, as was inferred that the range of proportion strengthened the ability of reactive oxygen species (ROS) scavenging. In
comparison with control, activity of POD, CAT and SOD of tea plants increased, butMP and RA fell under high Al and high F interaction, indicating that tea plants injured in some degree. Therefore, Al and F interac2tion has a significant effect on physiological and biochemical characteristics of young tea plants, and the proportion of interaction exist some range. The sensibilities between Baicha and Zhirenzaocha are different resulting from Al and F interaction and order is Zhirenzaocha >Baicha, which is suggested that there may be correlation with variety.

Key words: tea plants, aluminum, fluorine, Al and F interaction, physiological characteristics