镉胁迫对三叶鬼针草和荆芥种子萌发的影响

Effect of cadmium stress on seed germination in Bidens pilosa and Fineleaf schizonepeta

以三叶鬼针草和荆芥种子为材料,采用水培方法,研究镉对2种植物种子萌芽的毒害效应,结果表明,2种植物种子的发芽率、发芽势、发芽指数、活力指数、胚芽长度和胚根长度均随镉质量浓度的增加而降低.本试验条件下,低质量浓度(5 mg.L-1)的镉对荆芥种子的萌发有促进作用;高质量浓度镉对2种植物种子的萌发均有较强的抑制作用.由回归分析发现,2种植物的发芽抑制率和根伸长抑制率与镉浓度的相关性均达到显著性水平(P<0.05),有明显的剂量-效应关系.镉对2种植物种子的根伸长抑制率明显大于发芽抑制率.

Effect of cadmium stress on seed germination in Bidens pilosa and Fineleaf schizonepeta was studied by water cultivation experiments. The results showed that their germination rate, germination vigor, germination index, vigor index, embryo length and root length had significant negative correla- tion with the cadmium concentration. The germination of Fineleaf schizonepeta seed is promoted when the cadmium concentration is low （5 mg. L-1）. Their growth and germination were inhibited by the high cadmium concentration. The regression analysis reveals that there is significant correlation （P 〈 0.05） between their inhibition rates of seed germination, root elongation and the cadmium concentra- tion, which shows a significant dose-effect relationship. Their inhibition rates of root elongation exceed significantly their inhibition rates of seed germination.