ＰＥＧ处理对蛇皮果幼苗的生理响应及酶变化研究

以蛇皮果幼苗为试验材料，利用聚乙二醇 ６０００（ＰＥＧ ６０００）人工模拟水分胁迫环境，设置 ３个胁迫强度处理 （轻度胁迫、中度胁迫、重度胁迫）和 ３个胁迫持续时间处理 （持续 ２４，４８，７２ｈ），研究干旱胁迫对蛇皮果幼苗生理生化指标的影响。结果表明：随着 ＰＥＧ胁迫浓度的增加和胁迫持续时间延长，蛇皮果幼苗叶片相对含水量都表现下降的趋势，各胁迫处理都显著高于对照 （Ｐ＜０５）；叶片相对电导率呈上升的趋势，在处理 ４８，７２ｈ时，各浓度处理分别达到显著差异 （Ｐ＜０５）；叶片丙二醛和脯氨酸的含量均都有不同程度升高，重度胁迫处理时含量最高。不同浓度 ＰＥＧ处理在胁迫 ２４，４８，７２ｈ时，ＳＯＤ活性在处理 ２４ｈ表现最高，ＰＯＤ活性都表现为轻度胁迫时最高，ＰＰＯ酶活性都分别表现为随着胁迫浓度的增加而增强。在各种指标中，相对电导率、脯氨酸含量、丙二醛含量较为直观，可以作为评价蛇皮果苗木抗旱性的依据。

Biophysical Response and Enzyme Activity of Salak［Salacca zalacca (Gaertner) Voss］ to PEG Stress

The effect of drought on the seedlings was evaluated by testing the variance of physiological and biochemical parameters and this experiment were conducted using treatments of different polyethylene glycol (PEG 6000) concentrations (mild stress, moderate stress, severe stress) and different stress durations (24, 48, 72 h). The results indicated that the relative water content in leaves showed a decreased tendency with the increase of stress intensity and the treating time, and the control treatment was significant lower than other treatments (P＜0.05). The relative conductivity tended to increase and every treatment showed significant difference when treated with 48 h and 72h (P＜0.05); the proline and MDA content tended to increase and their highest values were attained under severe stress treatment; the highest activities of SOD, POD, PPO were attained when treated 24h, mild stress, severe stress, respectively The index of relative conductivity, MDA content and soluble sugar were intuitive and as proper physiological indices for evaluating drought resistance of seedlings of salak