盐胁迫下不同水稻基因型根内Na＋和Cl－的分布情况比较

应用Ｘ－射线显微分析技术比较了基本性状相似、但耐盐性显著不同的３组共６个水稻基因型的根内Ｎａ＋和Ｃｌ－分布情况。在盐胁迫下，耐盐基因型根内中柱的Ｎａ＋含量稍高于其它部位，而盐敏感基因型根中的Ｎａ＋则在整个横断面上分布得较为均匀，显示耐盐基因型根的中柱薄壁细胞对Ｎａ＋有相对积累作用，从而控制Ｎａ＋向地上部的运转。Ｃｌ－在所有基因型的根横断面上分布都较为均匀，耐盐与盐敏感基因型之间没有明显的差异

DISTRIBUTION OF Na AND Cl -IN THE ROOTS OF DIFFERENT RICE GENOTYPES UNDER SALT STRESS

The X ray microanalysis technique was employed to compare Na and Cl - distribution in the roots of six different rice genotypes which had similar general characters but marked differences in salt tolerance. Under NaCl stress, the content of Na in the stele parenchyma was relatively higher than in the other parts of the roots for the salt tolerant genotypes, while the Na content was evenly distributed in the roots for the salt sensitive genotypes, implying that the stele parenchyma might be the site controlling Na translocation from the root to the shoot. The Cl -distribution was relatively even across the roots of both salt tolerant and salt sensitive genotypes, suggesting that there might be other mechanisms controlling Cl - translocation.