Abstract: Two rice varieties, Xiushui 110 with high Cd tolerance and Xiushui 11 with low Cd tolerance were used to study the effects of cadmium (Cd) stress on seed germination, seedling growth and amylase activities. The low cadmium concentration had little effect on germination rate. However, cadmium stress could significantly inhibit plumule and radicle growth, especially for radicle growth. Germination index, vigour index, radicle length and amylase activities of Xiushui 11 decreased more significantly with the rising cadmium level compared with Xiushui 110. And the cadmium content in seedlings of Xiushui 11 was higher than that in Xiushui 110 when the cadmium concentration exceeded 5 μmol/L, which caused lower mitotic index in root tips and amylase activities, and more serious cadmium toxicity in Xiushui 11.

Key words: cadmium, rice, germination, root length, mitotic index, amylase activity

摘要： 以镉耐性不同的两个水稻品种秀水110(耐镉型)和秀水11(镉敏感型)的种子为材料，采用室内培养方法，研究了水稻种子萌发、幼苗生长和淀粉酶活性对Cd胁迫的响应。结果表明，在水稻种子萌发过程中，胚根和胚芽对Cd要比种子本身敏感，而胚根较胚芽更敏感。 Cd胁迫能显著影响发芽指数、活力指数、根长、淀粉酶活性，其中对秀水11的影响更明显；在高于5 μmol/L Cd浓度下，秀水11植株内的Cd含量明显高于秀水110，造成后者根尖有丝分裂指数和淀粉酶活性明显降低，受到的毒害更严重。

关键词: 镉, 水稻, 萌发, 根长, 有丝分裂指数