盐胁迫对砂蓝刺头不同器官中离子分布的影响  

Effects of salt stress on ion distribution in different Echinops gmelini organs

作　　者：杨小菊[1] 赵昕[1] 石勇[1] 李新荣[1] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所甘肃省寒区旱区逆境生理生态重点实验室,甘肃兰州730000

出　　处：《草业学报》2013年第4期116-122,共7页Acta Prataculturae Sinica

基　　金：国家自然科学基金(30770343;91125029)资助

摘　　要：砂蓝刺头为广泛分布于北方沙漠的一年生草本植物。本研究以砂蓝刺头幼苗为试材,采用营养液培养法研究了不同浓度NaCl胁迫下(盐浓度分别为0,100,200,300,400mmol/L)砂蓝刺头幼苗胁迫6d后植株含水量变化,测定不同器官中Na+、Cl-、Si 4+、K+、Ca2+的含量,并分析了K+/Na+、Ca2+/Na+、Si 4+/Na+值的变化。研究结果表明,盐胁迫下,砂蓝刺头幼苗含水量在盐处理浓度为100,200,300,400 mmol/L时分别比对照升高了9.86%,1.41%,4.23%,8.45%,说明盐胁迫下植株提高了组织含水量,这将在一定程度上稀释了体内盐离子,减弱盐胁迫造成的生理干旱。盐胁迫下砂蓝刺头根部的Na+和Cl-含量高于叶片,这有利于渗透调节,同时减弱了盐胁迫对地上部的毒害;根系Si 4+、K+、Ca2+的含量及K+/Na+、Ca2+/Na+、Si 4+/Na+值比对照显著性下降,叶部Si 4+、K+的含量和K+/Na+,Ca2+/Na+,Si 4+/Na+值比对照有所增加或差异不显著,这有利于维持地上部分离子稳定。分析离子选择性吸收的SNa+,K+数据发现,盐胁迫下砂蓝刺头根部拦截了部分Na+减缓了对地上部分的伤害,叶片对K+吸收具有很好的选择性,对于维持地上部分离子平衡和正常的光合作用具有重要意义。Echinops gmelini is an annual wild plant distributed in arid desert areas of North China. The changesof water content, Na＋ , C1- , Si4＋ , K＋ , Ca2＋ contents and the K＋/Na＋ , Ca2＋/Na＋ , Si4＋/Na＋ ratios weremeasured in E. gmelini seedlings in a water control and under different concentrations （100, 200, 300, 400mmol/L） of NaC1 stress： the water contents were found to increase by 9. 86%, 1.41%, 4. 23%, and 8.45%,respectively. Therefore the ability to absorb water was enhanced under salt stress, resulting in dilution of thecell＇s salt ion concentration to reduce physiological drought caused by salt ions. Na＋ and C1- contents of rootswere higher than those of leaves under salt stress, so the salt ion damage on the leaves was redueed The Si4% ,K＋ , Ca2＋ concentrations and K＋/Na＋, Ca2＋/Na＋ , Si4./Na＋ ratio in roots under salt stress were significantlyreduced compared with no salt stress. Based on the ion selective absorption of Nat and K＋ , E. gmelini rootsretained more Na＋ and reduced the Na＋ damage to leaves; The K＋ selective absorption to leaves of E. gmeliniwere strengthened under NaC1 stress, which was significant for maintaining iron homeostasis and photosynthe-sis in shoots.

关 键 词：砂蓝刺头 盐胁迫 离子分布 

分 类 号：S567.219[农业科学—中草药栽培]