Abstract: In order to probe the membrane structure and its related physiological changes in the tea leaves with fluorescent green spot disease, the diseased tea leaves were picked from the Fu Ding Da Bai tea plant cultivated in the nutritional solution with excessive calcium, and cellular membrane system was observed by transmission electron microcope, the electrolytic leakage, the contents of osmosis and the antioxidative enzyme activities of diseased tea leaves were determined. The results showed that the plasma membrane, chloroplast membrane, mitochondrion membrane, endoplasmic reticulum membrane and vacuole membrane in diseased tea leaves were damaged in different degree. With the extending of stress and the disease, the malondialdehyde (MDA) content and the electrolytic leakage increased, meanwhile the soluble sugar content, the soluble protein content and the free proline content increased rapidly in the diseased tea leaves. The activity of superoxide dismutase (SOD), peroxidase (POD) increased significantly at the initial stage of the diseased tea leaves, subsequently decreased, but their activities were higher than normal tea leaves. On the basis of above results, although the antioxidative enzyme activities were increased, it was incapable of reversing the damage of membrane system of the diseased tea leaves.

Key words: tea plant, tea fluorescent green spot disease, damage of membrane system, osmosis regulating substance, antioxidative enzyme activity