新疆野苹果幼苗对盐胁迫的生理响应

摘要

To explore the physiological response of Malus sieversii to salinity stress,Malus sieversii seedlings were cheared with six salinity levels (0,0.2%,0.4%,0.6%,0.8% and 1.0% NaCl) for 4 hours and seven time levels (0,4,8,12,16,20 and 24 hours) in 0.4% NaCl.Contents of proline,MDA,chlorophyll,and soluble sugar in leaves and activity of SOD and POD were mensurated.The results showed that proline content got the peak when NaCl concentration was 0.6% or 12 h in 0.4% NaCl,increasing 63.1% and 27.0% compared to control respec-tively.Increasing salt concentration and time resulted in higher levels for malondialdehyde content.Chlorophyll con-tent was decreased first,subseguently increased and decreased once more.Among all treatment they were lower than control.Soluble sugar content and the activity of SOD and POD were increased first,then decreased.The results in-dicated that Malus sieversii could reduce the damage to the plant by accumulating more proline and soluble sugar and increasing the activity of SOD and POD.It was adapted to salinity stress to some extent.%为了解新疆野苹果盐胁迫下的生理特性，以新疆野苹果实生幼苗为试材，设置6个 NaCl 梯度（0，0．2％，0.4％，0．6％，0．8％，1．0％）处理4 h 和0．4％NaCl 溶液处理7个时间梯度（0，4，8，12，16，20，24 h），采样测定其叶片中脯氨酸（Pro）、丙二醛（MDA）、叶绿素（Chl）和可溶性糖含量以及超氧化物歧化酶（SOD）和过氧化物酶（POD）活性的变化。结果表明：叶片中脯氨酸的含量在 NaCl 浓度为0．6％时和 NaCl 浓度为0．4％处理12 h 时，达到峰值，分别比对照提高了63．1％和27．0％。随着盐浓度的升高和盐胁迫时间的延长，丙二醛的含量呈现出逐渐增加的趋势。叶绿素变化呈现出先降低后升高再降低的趋势，所有处理中，叶绿素含量均低于正常水平。可溶性糖含量、SOD 和 POD 的活性均呈现先上升到达峰值后再下降的趋势。新疆野苹果幼苗在盐胁迫下可通过积累脯氨酸和可溶性糖，提高 SOD和 POD 的活性，以减缓盐胁迫对植株的伤害且具有一定的耐盐性。