Abstract: With soil culture experiment, this paper studied the effects of Cd on the seedling growth and root antioxidant system of Allium sativum roots. The results showed that under lower concentrations (<5 mg·L^-1) of Cd, the average fresh and dry mass per plant, root length and aboveground height increased slightly, root vigor, soluble protein content, SOD, POD and CAT activities increased obviously, and root antioxidant enzyme system still kept balance, reflecting in the little difference of root MDA content with the control. However, when the Cd concentration was higher than 5 mg·L^-1, the average fresh and dry mass per plant, root length and aboveground height decreased markedly, the increments of root vigor and soluble protein content abated, the balance of antioxidant enzyme system was broken, and the MDA content increased obviously. The study also showed the absorbed Cd by A. sativum was mainly accumulated in roots, and only small amount of Cd was transfered to the leaves.

Key words: Entomology, RAPD technique, Molecular genetic markers