铜胁迫对滇水金凤种子萌发及幼苗生长的影响

Effects of copper stress on seed germination and seedling growth of Impatiens uliginosa

为探讨铜对滇水金凤种子萌发和幼苗生长的影响,以云南常见乡土水生植物滇水金凤为材料,分别采用5种不同浓度铜溶液(0、2.5、5、10和15 mg/L)处理种子和幼苗,并测定其种子发芽率、发芽势、发芽指数、活力指数和吸水特性以及幼苗的株高、根长和茎粗等指标。结果表明:滇水金凤种子萌发随铜浓度升高呈“低促高抑”的现象,当铜浓度为5 mg/L时,滇水金凤种子萌发达到最高,其发芽率、发芽势和发芽指数与对照相比分别增加8.89%、12.22%和6.44;当铜浓度大于10 mg/L时,种子的各项发芽指标均逐渐降低,且高浓度铜胁迫能够提前2 d终止种子萌发活动,在铜胁迫的48 h内,滇水金凤种子吸水萌发活动随时间变化呈现“快-慢-快”的趋势。此外,滇水金凤幼苗对铜胁迫敏感,当铜胁迫浓度大于5 mg/L时,其幼苗生长发育受到显著抑制。

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.