Effects of Cadmium Stress on Seed Germination and Seedling Growth of Syringa oblata L.
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.
cadmium stressSyringa oblata L.seed germinationphysiological responseaccumulation and transport
万方数据
维普
