2种枸杞叶片对混合盐胁迫的生理响应

Physiological Responses of Two Kinds of Lycium barbarum Leaves to Mixed Salt Stress

选取耐盐性不同的‘宁杞5号’和‘黑杞1号’一年实生苗为试验材料,进行渗透势分别为-0.47、-0.82和-1.18MPa的混合盐(NaCl+Na_2SO_4)胁迫处理,分析比较2种枸杞叶片生理指标的响应特征,以揭示2种枸杞适应盐胁迫的生理机制。结果表明:(1)随着渗透势降低,2种枸杞叶片生理指标响应趋势基本一致,叶绿素(Chl)和可溶性蛋白(SP)含量先升后降,相对电导率、丙二醛(MDA)和脯氨酸(Pro)、可溶性糖(SS)含量逐渐增加,但‘宁杞5号’的变化幅度大于‘黑杞1号’。(2)随着渗透势降低,2种枸杞叶片的超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性均增强,但-1.18 MPa混合盐溶液处理则抑制了‘宁杞5号’抗氧化酶活性。(3)随着盐胁迫处理时间的延长,2种枸杞叶片相对电导率、MDA含量、Pro含量、SS含量和CAT活性增加,但‘宁杞5号’的渗透调节物质积累量高于相应‘黑杞1号’;而2种枸杞Chl含量及SOD和POD活性在-1.18 MPa混合盐溶液处理下有所下降。研究表明,2种枸杞均可通过积累渗透调节物质和加强抗氧化酶系统来缓解盐胁迫对自身的伤害,‘宁杞5号’的渗透调节能力较强,而‘黑杞1号’具有更稳定的抗氧化酶系统,从而具有更强耐受盐胁迫的能力。

In order to analyze the physiological response difference of Lycium barbarum to mixed salt（NaCl＋Na2SO4）,we selected one year seedling of‘NingqiNo.5’and‘HeiqiNo.1’as the materials,with dif-ferent salinity treatments under different osmotic potential gradients（-0.47,-0.82and -1.18 MPa,respectively）.The results showed that：（1）with the decreasing of osmotic potential,chlorophyll（Chl）and soluble protein（SP）contents increasedf irstly and then decreased.The relative conductivity,malondi-aldehyde（MDA）,proline（Pro）and soluble sugar（SS）contents gradually increased,but‘NingqiNo.5’trend is greater than ‘HeiqiNo.1’.（2）The activities of anti-oxidant enzyme superoxide dismutase（SOD）,peroxidase（POD）and catalase（CAT） increased,while the osmotic potential of-1.18MPa in-hibited the activities of anti-oxidant enzymes in ‘NingqiNo.5’.（3）With the prolongation of treatment time,MDA,Pro and SS contents and CAT activity increased in two kinds of L.barbarum,and the accu-mulation of‘NingqiNo.5’is higher than that of‘HeiqiNo.1’;while the content of Chl and the activities of SOD and POD decreased at-1.18MPa.All these results suggested that both types of L.barbarum can relieve salts tress by accumulating osmotic regulating substances and strengthening the antioxidant enzyme system.‘NingqiNo.5’has stronger osmotic adjustment ability,while‘HeiqiNo.1’has a more stable an-tioxidant enzyme system and thus has a stronger ability to tolerate salt stress.