Physiological and ecological responses of maize seedlings to cadmium stress

Maize seeds were soaked in solution with different concentration of cadmium (Cd 2+) and cultured routinely in doors.Germination of seeds and physiological and ecological responses of seedlings were studied.The results showed that Cd could affect germination of seeds and growth of maize seedling.Maize seed germination rate was inhibited when the concentration of Cd 2+ was higher than 50 mg·L -1.With Cd 2+ concentration increase,main root length and lateral root number were decreased.Cd 2+ could promote seedling height,dry matter weight of root and shoot when its concentration was lower than 5 mg·L -1.However,when the concentration was higher than 5 mg·L -1,inhibition effects could be observed,with the root activity and the content of chlorophyll reduced and malondialdehyde (MDA) content increased in root.Cd also affects the absorption of other mineral elements.For example,it could promote the absorption of Ca,Mg,Fe and Cu in root and shoot,and inhibit the absorption of K and Zn.