Abstract: In order to investigate the effects of copper on seed germination and seedling growth of I. uliginosa, a common native aquatic plant in Yunnan was used as material in this study. The seeds and seedlings were treated with 5 different concentrations of copper (0, 2.5, 5, 10 and 15 mg/L) respectively, the germination rate, germination potential, germination index, vigor index and water absorption characteristics of the seeds as well as the seedling height, root length and stem diameter were determined. The results showed that the seed germination of I. uliginosa had a phenomenon of low promotion and high inhibition with the increase of copper concentration. When the copper concentration was 5 mg/L, the seed germination reached the highest and the germination rate, germination potential and germination index increased by 8.89%, 12.22% and 6.44 compared with that of CK respectively. When the concentration of copper was more than 10 mg/L, the germination indexes of seeds decreased gradually, and the high concentration of copper could stop the germination activity 2 days earlier. Within 48 h of copper stress, the water absorption germination activity of I. uliginosa seeds showed a “fast-slow-fast” trend with time. In addition, the seedlings were sensitive to copper stress. When the copper stress concentration was more than 5 mg/L, the growth and development of the seedlings were significantly inhibited.

Key words: Impatiens uliginosa, copper stress, seed germination, water absorption characteristic, seedling growth