盐旱交叉胁迫对柽柳幼苗渗透调节物质含量的影响

以2年生柽柳幼苗为试验材料,采用盆栽模拟试验研究不同盐分和干旱胁迫对其叶片中渗透调节物质的影响,以探讨柽柳幼苗对盐旱交叉胁迫的适应性.结果表明:(1)随盐旱胁迫的不断加剧,幼苗叶片中可溶性糖含量呈先升高后降低的趋势,且中度和重度盐旱胁迫下均显著高于对照(CK).(2)幼苗叶片中脯氨酸含量在不同盐旱胁迫下均呈逐渐上升趋势,但在重度盐分和中度、重度干旱交叉胁迫下显著高于CK.(3)幼苗叶片中Na+、Cl含量在不同干旱胁迫下,随盐胁迫的加剧呈不同的变化规律,盐旱胁迫的各个处理水平下均显著高于CK,而K+、Ca2+、SO42-含量在轻度和重度干旱胁迫下随盐胁迫增强不断降低.(4)在中度盐旱胁迫下,K+、Ca2+含量与CK无明显差异.研究表明,柽柳幼苗中渗透调节物质在其抗旱耐盐性方面具有积极的调节作用；柽柳幼苗在盐旱胁迫下表现出一定的交叉适应性,适度的干旱胁迫能增强柽柳幼苗对盐分胁迫的耐受能力.

Changes of Osmotic Adjusting Substances in Leaves of Tamarix chinensis Seedlings under Salt and Drought Stress

To research the suitability of Tamarix chinensis seedlings to salt and drought stress,we studied the contents of osmotic adjusting substances in leaves of two years old T.chinensis seedlings under salt and drought stress by pot culture.The results showed that:(1)The soluble sugar content increased and then decreased with the stress intensified and kept higher than that of control under moderate and severe salt and drought stress.(2)The proline content increased with the stress intensified,but only significantly higher than that of control under the intercross stresses of severe salt and moderate and severe drought.(3)The contents of Na⁺ and Cl^- changed irregularly,and kept a significantly higher level than that of control under different stresses.(4)The contents of K⁺,Ca²⁺ and SO₄^2- decreased with the salt stresses intensified under light and severe drought stresses.Under moderate drought and salt stresses,the contents of K⁺ and Ca²⁺ had no difference with the control.Therefore,the osmotic adjusting substances played an active role on salt and drought resistance.In conclusion,T.chinensis seedlings showed some tolerance to salt and drought stresses,and appropriate drought stress could increase the resistance of T.chinensis to salt stress.