Abstract:

Rhododendron fortunei is one of the famous ornamental flowers in China, but its water conditions for growth are less known. Effects of soil water stress on antioxidant system and lipid peroxidation in the leaves of R. fortuneiwere investigated by using 5-year old pot-cultured seedlings as experimental materials and exposing them to different levels of water stress. Twelve pots of plant seedlings with a similar growth were divided into 4 groups: no stress (control), light stress, moderate stress and heavy stress. In comparison with no stress and light water stress, moderate stress and heavy stress resulted in significant increases in the malondiadehyde (MDA) content, generating rate of superoxide anion (O₂^-.), proline content, peroxidase(POD) activity and membrane permeability of leaf cells and significant decreasea in glutathione(GSH) content, carotenoid content and catalase (CAT) activity. However, the content of ascorbic acid (AsA), activities of superoxide dismutase (SOD) and ascorbate peroxidase (APX) exhibited another, i.g. increased under moderate water stress, but decreased under heavy water stress. The present conclusion is that R. fortunei growth can be inhibited through enhancing lipid peroxidation under heavy water stress.

Key words: Rhododendron fortunei, water stress, lipid peroxidation, antioxidant system