Response to Cadmium Stress at Seed Germination and Seedling Growth of Different Wheat Varieties

In order to clarify the response to Cd stress of different wheat varieties,the effects of cadmium(Cd) on seed germination,seedling growth and the activities of α-amylase and antioxidant enzymes were studied by using two wheat varieties,Fengyou 2 with low Cd tolerance and Fengyou 9870 with high Cd tolerance.The results showed that cadmium could significantly inhibit seedling growth,especially for root.Germination index,vigour index and root growth of Fengyou 2 decreased more significantly with the increase of cadmium level compared with Fengyou 9870.The content of MDA and activities of G-POD in root and shoot of wheat increased significantly with the increasing of Cd concentration.The activities of SOD first increased and then decreased as the Cd concentration increased.However,the activities of CAT and APX were decreased with concentration-dependent manner,ie,the higher concentration of cadmium,the greater changes of the enzyme activities.And the activities of α-amylase,CAT and APX in seedlings of Fengyou 2 was significant lower than those in Fengyou 9870 at relative high cadmium concentration,which caused more serious cadmium toxicity on Fengyou 2.