中文摘要：

为了明确不同品种小麦种子萌发和幼苗生长对Cd胁迫响应的差异，以对Cd耐性不同的2个小麦品种（丰优2号和丰优9870）为材料，研究了Cd胁迫对小麦种子萌发、幼苗生长、α-淀粉酶和抗氧化酶活性的影响。结果表明，Cd胁迫显著影响了发芽指数、活力指数和根生长，幼苗根和芽要比种子萌发对Cd敏感，根较芽更敏感。随着Cd2＋浓度的增加，幼苗根、叶中的MDA含量、G-POD活性明显增加，SOD活性呈现先增加后降低的趋势，而CAT、APX和α-淀粉酶活性呈下降趋势，且Cd2＋浓度越高下降幅度越大。两个小麦品种在种子萌发过程中受Cd的毒害程度不同，其中对丰优2号的影响更明显，在较高浓度Cd2＋胁迫下，丰优2号的α-淀粉酶、CAT、APX活性明显低于耐Cd品种丰优9870，说明Cd胁迫对前者的毒害更严重。

英文摘要：

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.