土壤盐胁迫对海州常山生理生化特性的影响

Effect of Soil NaCl Stress on Physiological and Biochemical Characteristics of Clerodendrum trichotonum Thumb

采用盆栽试验方法,研究0-0.8%不同梯度盐（NaCl）胁迫对1 a生海州常山播种苗生长特征和叶片生理生化特性的影响。结果表明,盐胁迫对海州常山叶片相对含水量、质膜相对透性、SOD与POD酶活性、脯氨酸及可溶性糖含量均发生明显的变化。随着盐分胁迫浓度增大和胁迫时间的延长,新梢和功能叶片逐渐失绿甚至焦边枯黄,叶片相对含水量逐渐降低,细胞相对质膜透性逐渐增大,脯氨酸与可溶性糖含量逐渐增加,SOD与POD酶活性出现先升高后降低的趋势。相关分析表明,在低、中度（0.2%、0.4%）盐胁迫下,海州常山生理生化指标变化不显著,等于或大于0.6%盐胁迫下生理生化指标变化显著,由此认为0.6%是海州常山盐胁迫的阀值。

The effect of different soil NaCl concentration stress on morphological and physiological characteristics of one year old Clerodendrum trichotomum Thumb seedlings was studied. The results showed that soil NaCl stress caused significant changes in leaf morphological characteristics,leaf relative water content, relative permeability of the plasma membrane, activity of SOD and POD, content of free Proline and soluble sugar. With NaCl stress concentration increasing and time prolonging, new top leaf and function leaf changed gradually with yellowness even burnt side, content of leaf relative water decreased gradually, cell membrane permeability expanded gradually, content of proline and soluble sugar increased gradually, at first, activity of SOD and POD increased, but later it decreased. Composite index analysis showed that the effect of low and moderate NaCI stress on physiological and biochemical characteristics of Clerodendrum trichotomum Thumb did not changesignificandy, but the effect of equal or more than 0.6% NaCI stress on physiological and biochemical characteristics changed significantly, which could be considered that 0.6% is the NaCl stress threshold of Clerodendrum trichotomum Thumb.