镉对不同基因型水稻生长毒害影响的比较研究

Comparative Study on Cd Phytotoxicity to Different Genes of Rice.

利用水培分期添加镉试验，研究了杂交水稻和常规水稻在不同生育时期对环境镉毒害的反应。结果表明，在水稻幼穗分化之前，镉主要降低光合生产力，影响植株生长；幼穗分化至抽穗期，主要抑制生殖器官分化，造成颖花败育；抽穗期之后，镉主要干扰体内营养物质的迁移和再分配。就对产量影响而言，幼穗分化至抽穗期是水稻对镉反应最敏感时期，杂交稻比常规稻对镉污染毒害敏感。

A study on Cd phytotoxicity to hybrid rice and conventional rice at different growth stages was conducted using water cultures.The results showed that the principal toxic effects of Cd on rice before ear initiation were the reduction of the photosynthetic production,with as typical features:the hardening of roots,yellowed leaves,and emaciated vegetation.In the stages from ear initiation to heading,the main phytotoxicity of Cd was inhibition of the differentiation and development of the reproductive organs which lead to luxuriantly tillering and sterility of caryopses.After the heading stage, the main effects of Cd toxicity were that the transport and redistribution of nutrients in vivo were disturbed.Typical features were the appearance of a large numher of later tilleis and pooly mature rice.The largest influence of Cd on rice nutrition appeared to be the reduction of the physiological availability of nutrient elements(N,P,K) absorbed by rice plants.and the increased accumulation of these elements in rice leaves and straws at the ripening stage.As to the effect of rice yield(brown rice),the most sensitive stage for both rice genes to Cd toxicity was from ear initiation to heading. Hybrid rice was more sensitive than conventional rice to Cd pollution.