摘要
通过对自然生境下盐角草的离子及部分重金属元素吸收-运输特性的分析，结果表明：①盐角草地上部Cl^-，Na^＋，K^＋含量显著（P≤0．05）大于地下部；②盐角草的离子吸收选择顺序为K^＋〉Mg^2＋〉Cl^-〉Na^＋〉SO4^2-〉Ca^2＋，而运输选择顺序为Na^＋〉Cl^-〉K^＋〉Mg^2＋〉SO4^2-〉Ca^2＋，反映了盐角草对离子（特别是K^＋，Na^＋，Cl^-）的优先选择性在吸收和运输方面的不同；③选择性比率SK,Na〉SMg，Na〉SCa，Na，说明稳定体内K^＋／Na^＋是盐角草耐盐的重要机制；④盐角草的离子吸收和运输存在一个梯度：根系相对于土壤介质，离子的吸收倍数为3．7～129．4；地上部相对于根的运输倍数为1．1～2．8，这种从土壤→根系→地上部离子转运成倍数的累积，既保证营养吸收的需求，又保证了低水势的维持；⑤污灌区盐角草的重金属含量除Cu外，Cd，Pb，As均是地下部含量〉地上部；Cu在地上部的富集系数〉1，As在地下部的富集系数为2．6，反映了盐角草对Cu，As的不同富集能力，因此，盐角草可用于盐渍化土壤重金属污染后的修复。
In this paper, the ionic absorption and transport of Salicornia europaea L. and some heavy metals in it are studied. The results are as follows： （1） The contents of Cl^-, Na^＋, K^＋ in aerial part of S. europaea L. are significantly （P ≤ 0.05） higher than that in roots; （2） The ionic absorption ratio of S. europaea L. is in an order of K^＋〉Mg^2＋〉Cl^-〉Na^＋〉SO4^2-〉Ca^2＋ , and the ionic transport ratio is in an order of Na^＋〉Cl^-〉K^＋〉Mg^2＋〉SO4^2-〉Ca^2＋, which reveal the selectivity difference in ionic absorption and transport in S. europaea L. ; （3） The ionic selectivity ratio in S. europaea L. is in an order of SK, Na〉SMg,Na〉SCa,Na, which reveals that it is a critical factor to stabilize the value of K^＋/Na^＋ in S. europaea L. for its salt resistance; （4） There is certain gradient of ionic absorption and transport of S. europaea L., that is the ionic absorption of S. europaea L. roots is 3.7- 129.4 times of that of substrate soil, and the ionic transport of aerial part is 1.1-2.8 times of that of roots. Such diploid ionic accumulation in the soil-root-aerial-part system can not only satisfy the alimentation of S. europaea L., but can also maintain a low water potential; （5） The contents of Cd, Pb and As in S. europaea L, roots are higher than that in aerial part except Cu in the wastewater irrigation region, the enrichment coefficient of Cu in aerial part is higher than 1, and the enrichment coefficient of As in roots is 2.6, which reveal that S. europaea L. has a special capability of enriching Cu and As. Therefore, S. europaea L. can be planted as a halophyte for regenerating vegetation after salinized soil is polluted by heavy metals.
出处
《干旱区研究》
CSCD
北大核心
2007年第4期480-486,共7页
Arid Zone Research
基金
重大基础研究前期研究专项项目(2005CCA02700)
自治区科技攻关项目(200533126)
