混合盐碱胁迫对柳树幼苗生理指标的影响

为研究混合盐碱胁迫对柳树幼苗叶片含水量、光合色素质量分数和抗氧化酶活性的影响,以盐柳1号(Salix psammophila‘Yanliu NO.1’)无性系幼苗为材料,对其进行12组不同浓度和组分的混合盐碱胁迫处理。研究结果表明:盐柳1号幼苗的叶片含水量下降的趋势随着盐浓度的增高和pH值的增大而明显加剧。B处理组的盐柳1号幼苗的叶片叶绿素a质量分数在盐浓度高于150 mmol/L时显著下降(P<0.05),A、C处理组的盐柳1号幼苗的叶片叶绿素a、叶绿素b质量分数均无显著变化(P>0.05)。在小于150 mmol/L的混合盐碱胁迫下,随着盐浓度的增高,各处理组盐柳1号幼苗的叶片SOD、POD、CAT活性增强或显著增强,在盐浓度高于150 mmol/L时,盐柳1号幼苗的叶片SOD、POD、CAT活性下降,其中,C处理组盐柳1号幼苗的叶片在盐浓度大于150 mmol/L时全部枯黄。综合各项结果,盐浓度在150 mmol/L以下,pH小于9.51时,盐柳1号幼苗具有较好的耐受能力,可以抵御一定的盐碱胁迫。

Effects of Mixed Saline-alkali Stress on the Physiological Indexes of Willow Seedlings

This experiment was conducted to investigate the response of leaf water content, photosynthetic pigment content and antioxidant enzyme activity of Salix psammophila ‘Yanliu NO.1’ under complex salt-alkali stress. The seedlings were treated with 12 types of saline-alkali stress with different salinity and alkalinity levels. The decreasing trend of relative water content in leaves of S. psammophila ‘Yanliu NO.1’ seedling were aggravated with the increasing salt concentrations and the proportion of alkaline salts. The content Chla in the leaves of S. psammophila ‘Yanliu NO.1’ seedlings under treatment B significantly decreased when the salt concentration was higher than 150 mmol/L(P<0.05), while the contents of Chla and Chlb in the leaves under treatment group A and C showed no significant change(P>0.05). In the range of salt concentration below 150 mmol/L, the activities of SOD, POD and CAT in the leaves of S. psammophila ‘Yanliu NO.1’ seedlings increased with the increasing salt concentrations. When the salt content was higher than 150 mmol/L, the activities of SOD, POD, and CAT were decreased to some extent, and the leaves of S. psammophila ‘Yanliu NO.1’ seedlings under treatment C withered. Therefore, S. psammophila ‘Yanliu NO.1’ seedings had a high tolerance to complex saline-alkali stress when the salinity was <150 mmol/L and pH was <9.51.