根表铁膜、锰膜对水稻铝吸收和运输的影响

Effects of iron and manganese plaques on aluminum uptake and translocation by rice seedlings

以耐铝水稻品种菲优多系1号和铝敏感水稻品种红良优166为材料,通过溶液培养试验研究根表铁膜、锰膜和铁-锰膜对铝吸收和运输的影响.结果表明:铁膜、锰膜和铁-锰膜诱导形成后,水稻根表的铁膜厚度大于锰膜厚度,铁-锰膜中铁占主要部分,锰含量极少,仅占胶膜总量的0.12%～0.20%;铝胁迫下根相对伸长率在不同处理间表现为锰膜>铁-锰膜>铁膜>无膜,铝含量和积累量在植株各部分表现为根表>根系>地上部;耐铝品种菲优多系1号和铝敏感品种红良优166分别有91%和85%以上的铝分布在根表胶膜中,表明耐铝品种根表铁-锰膜能更有效地将铝阻挡在根外,减少根系对铝的吸收并向地上部运输,其中锰膜的斥铝效果好于铁膜.

A hydroponic experiment was conducted to investigate the influence of iron and manganese plaque on Al uptake and accumulation of Feiyouduoxi No.1 （Al-resistant rice cultivar） and Hongliangyou 166 （Al-sensitive rice cultivar）.The formation of iron plaque,manganese plaque and iron/manganese plaque was induced by exposing the rice roots to 0.8 mol·L^-1 Fe^2＋ or Mn^2＋,and the quantity of iron plaque was much more than that of manganese plaque.Most Fe was found in mixture of iron/manganese plaque,while Mn was much less and only accounted for 0.12%-0.20% of the total.Relative root elongation rate of rice seedlings under Al toxicity showed the following rank order：manganese plaque〉iron/manganese plaque〉iron plaque〉no plaque.Al contents and accumulation in whole rice seedlings showed the following rank order：root surface with plaque〉root〉shoot.Ninety-one percent and eighty-five percent of Al was present in the root surface plaque of Al-tolerant Feiyouduoxi No.1 and Al-sensitive Hongliangyou 166,respectively,indicating that Al-resistant cultivar was more efficient to exclude Al from root and reduce the translocation of Al from root to shoot.Manganese plaque exerted more pronounced effect in Al tolerance.