Abstract:Rice (Oryza sativa L.) seed was treated with different concentrations (0, 20, 50, 100 and 300 mg·L-1) of KClO4 solution.Seed germination, growth and physiological characteristcs of seedling under hydroponic and controlled conditions were determined. The results showed that low concentration (20 mg·L-1) of KClO4 treatment stimulated seed germination with a higher germination index, root length and root number of seedlings than those of the control (CK). With an increase of KClO4 concentration and treatment time, seed germination and seedling growth were gradually inhibited, and such an inhibition effect of KClO4 was greater on stems than on the roots of seedlings. With an increase of KClO4 concentration, chlorophyll content, soluble protein and MDA content, CAT activity decreased. The POD activity increased. The SOD activity increased first, then decreased in seedling leaves compared to the control. The results of correlation analysis between different indexes suggested that the inhibition of seed germination and physiological damage of rice seedling under KClO4 stress might be related to disturbance of active oxygen metabolism in KClO4-treated seeds and seedlings. The damage mechanism caused by KClO4 need to be further studied.
