多花胡枝子对干旱胁迫的生理响应初步研究

实验采用聚乙二醇6000(PEG6000)在室内模拟干旱条件,研究不同程度干旱胁迫对多花胡枝子相对含水量、相对电导率、丙二醛(MDA)、叶绿素含量、超氧化物歧化酶(SOD)活力和脯氨酸含量的影响,旨在探求其在沙质条件下的生存能力.结果表明:随着干旱胁迫的加强,电导率和丙二醛(MDA)明显增加,而叶绿素含量、超氧化物歧化酶(SOD)活性和叶片相对含水量均呈显著下降趋势.以30%PEG6000处理对多花胡枝子的伤害最大.在胁迫处理12h,30%浓度处理的植株电导率高至(50.7%)比对照组高13.4%;SOD活性最低为100.4 U/g;在胁迫处理24h时,10%浓度处理的植株脯氨酸含量高达1 024 Ug/g,此后逐渐降低;在处理48h时,30%浓度处理的植株MDA含量为17.58 nmol/g,高于其他胁迫处理.在PEG6000处理过程中,处理0~12h为植株的抗性阶段,处理12~48h为植株的耗尽阶段.可见,在干旱胁迫下,多花胡枝子可以通过改变体内物质含量来提高抗性,渡过逆境.

Research on Physiological Response of Lespedeza Floribunda to Drought Stress

Using Lespedeza floribunda as material,the physiological changes characteristics of the plant were studied under drought stress in order to explore the survival ability on sandy conditions.The results showed that with drought stress increasing,conductivity and malondialdehyde（MDA） content increased significantly,conductivity increased 40.3 percentage points and MDA increased from 4.34 nmol/g to14.9 nmol/g,and Chlorophyll content、superoxide dismutase（SOD） activity and leaf relative water content decreased,which is 3.12%、98.15 U/g and 45% respectively,free praline content as a good drought-resistant index,changed significantly,firstly increased to 1204 Ug/g and then decreased to 749 Ug/g.During the drought stress,Lespedeza floribunda showed a good ecological adaptation.