铵态氮/硝态氮对水稻铝吸收的影响及其机制研究

Effects and Mechanisms of NH_4^+/NO_3^- on Al Uptake by Rice

选用两个水稻品种武运粳7号(耐铝品种)和扬稻6号(铝敏感品种)作为实验材料,利用水培试验,通过长期和短期处理相结合的方式研究了NH4+-N和NO3--N对水稻Al吸收的影响及其作用机制。结果表明,与NH4+-N相比,NO3--N促进了水稻对Al的吸收。而且随着NO3--N浓度的提高,水稻根中Al含量显著增加,随着NH4+-N浓度的提高,水稻根中Al含量显著降低。这些结果表明NH4+-N和NO3--N对水稻Al吸收的影响具有浓度效应。当向Al溶液添加pH缓冲剂后,NH4+-N和NO3--N对根尖Al累积的影响变小,表明NH4+-N和NO3--N处理下溶液pH的变化可能是NH4+-N和NO3--N对水稻Al吸收影响不同的一个原因。

In this study,two rice cultivars,Wuyunjing7（Al-tolerant） and Yangdao6（Al-sensitive）,as experimental materials in rice hydroponic experiments were selected to investigate the effects of different N forms on Al toxicity through long-term and short-term treatment.Results showed that compared with NH4^＋,NO3^-increased Al uptake by rice,Al content in root increased significantly with the increase of NO3-concentration but decreased significantly with the increase of NH4^＋ concentration.These results showed that the effects of NH4^＋ and NO3^-on Al uptake by rice had a concentration-effect.When pH buffer was used,the difference in Al accumulation in root decreased between NH4^＋ and NO3^-supply,which demonstrated that the difference in pH values of the NH4^＋ and NO3^-solution may be the reason for the different Al contents of roots under NH4^＋ and NO3^-supply.