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以马齿苋幼苗为试验材料,研究了沙培条件下,0、100和200 mmol·L~(-1)NaCl处理对其生长及不同器官中Na~+、K~+、Ca~(2+)和Mg~(2+)分布的影响。结果表明:不同浓度NaCl处理下,马齿苋幼苗地上部干质量及单株叶片数均有所下降,但根系干质量和根冠比均有不同程度的增加。根、茎、叶中Na~+含量较对照均显著升高,且主要储存于根中;K~+含量较对照显著下降,茎中K~+含量降幅较小,而叶片中降幅较大;叶片中Ca~(2+)和Mg~(2+)含量显著高于茎和根。根、茎、叶中K~+/Na~+、Ca~(2+)/Na~+、Mg~(2+)/Na~+比值随NaCl处理浓度的增加而降低,主要原因是Na~+净增加;但叶片中K~+/Na~+、Ca~(2+)/Na~+、Mg~(2+)/Na~+比值显著高于茎和根系。随着Na Cl浓度的增加,马齿苋幼苗从根到茎的离子选择性运输能力先升高后降低,而茎到叶片的离子选择性能力总体呈升高趋势。综合分析表明,马齿苋可能通过将Na~+区域化到根系中,并增强植株向茎叶选择运输K~+、Ca~(2+)和Mg~(2+)的能力,从而缓解NaCl处理对马齿苋的伤害。
Taking Portulaca oleracea seedlings as test material, the effects of 0, 100 and 200 mmol·L -1 NaCl on the growth and the contents of Na ~ +, K ~ +, Ca ~ (2) in different organs +) And Mg ~ (2+) distribution. The results showed that the dry weight and the number of leaves per plant of Portulaca oleracea seedlings decreased with different NaCl concentrations, but the root dry weight and the ratio of root to shoot increased in different degrees. The contents of Na ~ + in roots, stems and leaves were significantly increased compared with the control, and were mainly stored in the roots. The content of K ~ + decreased significantly compared with the control, while the content of K ~ + decreased slightly in the stems, but decreased in the leaves. The contents of Ca 2+ and Mg 2+ in leaves were significantly higher than those in stems and roots. The ratio of K ~ + / Na ~ +, Ca ~ (2 +) / Na ~ + and Mg ~ (2 +) / Na ~ + in roots, stems and leaves decreased with the increase of NaCl concentration, + Net increase; but the ratio of K ~ + / Na ~ +, Ca ~ (2 +) / Na ~ + and Mg ~ (2 +) / Na ~ + in leaves was significantly higher than that in stems and roots. With the increase of NaCl concentration, the ion-selective transport capacity of the purslane seedlings from root to stem increased first and then decreased, while the ion-selective ability from stem to leaf showed an overall upward trend. Comprehensive analysis showed that purslane could alleviate NaCl through the regionalization of Na ~ + into roots and the ability of plants to transport K ~ +, Ca ~ (2+) and Mg ~ (2+) selectively to shoots and leaves Deal with the damage to purslane.