Cu^(2+)胁迫对生菜种子萌发和幼苗生理特性的影响

Effects of Cu^(2+) Stress on Seed Germination and Seedling Physiological Characteristics of Lettuce

以生菜种子为研究材料,通过水培试验,分别用不同质量浓度(0,5,10,20,50,80,120 mg/L)Cu^(2+)溶液对生菜种子进行浸种及培养,研究Cu^(2+)对生菜种子萌发及幼苗初期生长的影响。结果表明,在低质量浓度Cu^(2+)(5～10 mg/L)作用下,生菜种子的发芽率、发芽势和发芽指数呈上升趋势;在高质量浓度Cu^(2+)(20～120 mg/L)作用下,生菜种子的发芽势、发芽率及发芽指数呈下降趋势。随着Cu^(2+)浓度的升高,生菜幼苗的株高和根长均呈现降低趋势,幼苗中SOD,POD活性和叶绿素含量均呈现出先升高后降低的趋势。低质量浓度的Cu^(2+)溶液对生菜种子的萌发具有一定的促进作用,但对于生菜幼苗的生长不利,且随着处理浓度的增高,对生菜种子的萌发及幼苗的生长抑制作用明显增强,生菜的SOD,POD活性在50 mg/L时最大。

The hydroponic culture method was adopted to test the effects of different concentrations of Cu2+on seed germination and seedling growth of lettuce.The results showed that Cu2+solution with low concentrations(5-10 mg/L)had a promoting effect on seed germination force,germination rate and germination index of lettuce.Cu2+solution with high concentrations(20-120 mg/L)had an inhibitory effect on seed germination force,germination rate and germination index of lettuce.With the increase of Cu2+concentration,the root length and the height of seedling decreased,however the chlorophyll content,activities of SOD and POD increased firstly and then decreased slightly.Low concentration of Cu2+solution can promote the germination of lettuce seeds,but it is not conducive to the growth of lettuce seedlings.With the increase of treatment concentration,the inhibition of lettuce seed germination and seedling growth increased significantly.The activity of SOD and POD in lettuce reach the maximum at 50 mg/L.