【摘要】 采用营养液水培,以2个耐盐性不同的黄瓜品种为材料,研究了不同浓度NaCl处理下幼苗植株体内K+、Na+和Cl-在器官间的区域化分布及其吸收和运输特性的变化。结果表明:NaCl胁迫下,黄瓜植株体内K+含量下降,Na+和Cl-含量升高,变化幅度随NaCl浓度的升高而增大;不同器官间,茎中Na+和Cl-含量最高,上位叶中Na+和Cl-含量最低、K+含量下降幅度最小。与耐盐性较弱的“津春2号”相比,耐盐性较强的“长春密刺”根向茎运输的SK,Na值较高,根系对Na+的截留作用较强,茎向上位叶运输的SK,Na和SCl,Na值均较高,叶片中K+含量下降幅度较小,K/Na和Cl/Na比值均较高,功能叶中盐分离子尤其是Na+积累较少,植株生物量较高。说明根系对Na+的截留能力较强且向上位叶运输Na+的选择性较低,是“长春密刺”耐盐性较强的主要原因之一。更多还原

【Abstract】 By the method of hydroponics,this paper studied the effects of different concentration NaCl on the allocation of K+,Na+ and Cl-in the seedlings of two Cucumis sativus L.cultivars with different levels of salt-tolerance.The results showed that under NaCl stress,the seedlings K+ content decreased,while their Na+ and Cl-contents increased,with the increase in salinity.Among the test organs,stem had the highest content of Na+ and Cl-,while upper leaves had the lowest.The decrease of K+ content in upper leaves was less than that in other organs.Compared with salt-susceptible cultivar ’Jinchun No.2’,salt-resistant cultivar ’Changchun Mici’ had a higher transportation selectivity of K+ to Na+ from root to stem,and of K+ to Na+ and Cl-to Na+ from stem to upper leaves,and retained more Na+ in root.As a result,’Changchun Mici’ accumulated more K+ and less Na+ in its leaves,and the ratios of leaf K/Na and Cl/Na were higher.’Changchun Mici’ also had a higher biomass than ’Jinchun No.2’ under same salinity.All of these suggested that the higher accumulation of Na+ in roots and the lower transportation selectivity of Na+ from stem to upper leaves were the main reasons for the stronger salt-tolerance of ’Changchun Mici’.更多还原