盐胁迫及外源Ca2+对白刺离子吸收、运输的影响

摘要

以唐古特白刺（Nitraria tangutorum Bobr.）为试验材料，研究不同浓度盐胁迫对白刺离子吸收和分布的影响及外源Ca2+的调控效应。结果表明，随盐浓度的升高，白刺单株生物量及叶片肉质化程度增加，根系对Na+、Cl-的吸收大幅增加，对K+、Ca2+的吸收则逐渐降低，且Na+、K+、Ca2+主要集中在地上部。添加外源Ca2+有效降低白刺根系对Na+的吸收，增强对K+、Ca2+的选择吸收，根、茎对K+、Ca2+的运输选择性高于Na+，有效降低茎、叶中Na+含量，说明离子区域化是盐生植物白刺的重要耐盐机制，外源Ca2+能有效降低植物体内Na+水平，缓解盐胁迫对植物的伤害。%An experiment was conducted to study the effects of different concentrations of salt stress on ion uptake and distribution of Nitraria tangutorum Bobr. and the regulation effects of exogenous Ca2+. The results showed that with the increase of salt concentration, single plant biomass and the degree of leaf succulence elevated, and the absorption of root for Na+and Cl-substantial y increased, while for K+and Ca2+decreased, and Na+, K+and Ca2+mainly concentrated in the shoot. Exogenous Ca2+effectively reduced the Na+absorption of roots and enhanced the selective absorption of K+and Ca2+. The transportion selectivity of K+and Ca2+in roots and stems were higher than that of Na+, which was effective to reduce the Na+content of stems and leaves. The results suggested that ion compartmentalization was an important salt tolerant mechanism of N. tangutorum, and exogenous Ca2+ could effectively reduce the Na+ content in plants and relieve salt stress damage on plant.