Abstract: By the method of water culture, this paper studied the effects of 1,2,4-trichlorobenzene (1,2,4-TCB) on the seed germination and seedling growth of rice, with the chlorophyll, protein and proline contents and cytomembrane permeability of seedling leaf measured. The results showed the seed germination rate and vigor index were decreased with increasing concentration of 1,2,4-TCB, showing a definite dose-response relationship, and the seedling growth and root length were inhibited, showing definite time-response and dose-response relationships. The chlorophyll a, chlorophyll b, total chlorophyll, and protein contents in seedling leaf decreased with increasing concentration of 1,2,4-TCB, while the free proline content and cytomembrane permeability had a sharp increase when the concentration of 1,2,4-TCB was higher than 15 mg·L^-1. All of these suggested that the damage of rice seedling was a complicated process, which might be related to the structural and functional damage of cellular membrane, protein, and organelles.

Key words: Aquatic ectoenzyme, Red tide, Eutrophication, Alkaline phosphatase