In this paper,Syringa oblata L.seeds and seedlings were used as research object,and the effects of different concentrations of cadmium(0,5 mg/L,10 mg/L,20 mg/L,30 mg/L,40 mg/L)stress on seed germination,seedling growth physiological characteristics and cadmium accumulation characteristics were analyzed.The results showed that with the increase of cadmium stress concentra-tion,the germination index of seeds increased first and then decreased,and the germination rate was the highest when the stress concentration was 5 mg/L.Abnormal germination rate significantly increased when stress concentration was greater than 10 mg/L(p＜0.05).According to the regression analysis,the semi-lethal concentration of cadmium stress on seed germination was 29.95 mg/L,and the limit concentration was 50.41 mg/L.The inhibitory effect of cadmium stress on radicle growth was higher than that of germ.With the increase of cadmium stress concentration,the above-ground and underground dry weight and root-shoot ratio of seedlings showed a decreasing trend,and the root activity,antioxidant enzyme activity and osmotic regulatory substance contents increased first and then decreased,reaching the highest at the stress concentration of 10 mg/L.The MDA content and plasma membrane permeability showed an increasing trend,but there was no significant difference compared with the control at the stress concentration of less than 10 mg/L.The highest Cd transfer coefficient was 0.54 when the stress concentration was 10 mg/L,and the accumulation amount was 1.25 mg/g.These results indicated that when the cadmium stress concentration was lower than 10 mg/L,Syringa oblata L.seedlings could maintain normal growth by adjusting their physiological activity and had a certain tolerance to cadmium stress.
关键词
镉胁迫/紫丁香/种子萌发/生理响应/积累转运
Key words
cadmium stress/Syringa oblata L./seed germination/physiological response/accumulation and transport
维普
万方数据