Abstract:

In this paper, Potentilla sericea was used as experimental material, and subjected to different concentrations of heavy metal cadmium (Cd) stress. The structure of plant, and physiological responses was studied after Cd treatment. The results showed that:under Cd stress, with the accumulation of Cd, the double membrane structure of the chloroplast disappeared, the thylakoid fuzzy scattered, addicted to osmium particle size enlarged and the number of starch grains increased, even the disintegration of the chloroplast. The content of chlorophyll and soluble protein were declined with the increase of time and Cd concentrations. Proline content increased significantly. Superoxide dismutase (SOD) activity showed a trend of decline after rising at the begin of Cd treatment. The study showed that with the increase of Cd concentration, the toxicity of Cd to Potentilla sericea seedling increased. The Cd tolerance of Potentilla sericea seedling was below 2 mg·kg^-1.

Key words: Potentilla sericea, The heavy metal cadmium, Leaf ultrastructure, Physiological characteristics

摘要：

本文以绢毛委陵菜为试验材料，从结构特点和生理特性两方面研究了绢毛委陵菜在镉胁迫下的反应机理，结果表明：绢毛委陵菜在受到镉胁迫时，随着重金属含量的积累，叶绿体结构的双层膜破裂消失，类囊体模糊散乱，嗜锇颗粒变大增多，淀粉粒增大，直到叶绿体解体。叶绿素含量和可溶性蛋白的含量随镉胁迫时间以及浓度的增加，不断降低；脯氨酸含量显著上升；超氧化物歧化酶活性呈先升高后降低的趋势。研究表明镉胁迫浓度越高，绢毛委陵菜幼苗所受毒害越大，绢毛委陵菜对镉的耐受程度为2 mg·kg^-1以下。

关键词: 绢毛委陵菜, 重金属镉, 叶片超微结构, 生理特性