水稻耐盐机理的研究Ⅲ.不同基因型对NaCl吸收和运转的动力学比较

STUDIES ON THE MECHANISMS OF SALT TOLERANCE IN RICEⅢ.COMPARISON OF KINETEC OF NACL ABSORPTION ANDTRANSLOCATION AMONG DIFFERENT GENOTYPES

本文应用动力学研究方法比较了具有不同耐盐性的3组共6个水稻基因型对NaCl吸收和运转的差异,结果表明,在外部低NaCl浓度(0.1mmolL^(-1)时,水稻对Na^+的吸收为被动吸收,耐盐基因型对Na^+的吸收速率显著低于盐敏感基因型;对Cl^-的吸收为主动吸收,不同耐盐性基因型吸收Cl^-的动力学参数(V_(?)、K_(?))差异不显著,在外部高NaCl浓度(50mmolL^(-1))时,耐盐基因型对Na^+和cl^-的吸收速率均低于对应的盐敏感基因型。耐盐基因型水稻的Na^+、cl-从根部向地上部的运转率低于对应的盐敏感基因型,这种差异在高盐浓度时更为明显。表明了耐盐基因型水稻地上部对NaCl的排斥作用是吸收控制和运转控制共同作用的结果,使地上部Na^+、Cl-含量相对降低而显出较高的耐盐性。

Three pairs of rice genotypes,each pair having similar general characters but marked differences in salt tolerance ,were compared in terms of seedling responeses to Nacl stress.Based on such growth indices as appearance evaluation of salt damage relative biomass and fresh/dry matter ratios,it was confirmed that the salt-tolerance genotypes indeed outdid their salt-sensitive counterparts It was found from plant tissue analysis that Na+or Cl-content in the shoot of salt-to-lerant genotypes was significantly Lower than those of salt-sensitive genotypes.Correlation analysis showed that the Na+or Cl-ccntent in the shoot was highly correlated to the above growth indces ,indicating that Na+and/or Cl-content in the shoot can be used as a physiological index of salt tolerance in rice seedlings.