水分胁迫对黄连木幼苗的生理响应

Physiological Response of Pistacia chinesis Seedlings to Water Stress

[目的]了解黄连木幼苗在水分胁迫下生理特性的变化。[方法]以黄连木1年生盆栽苗为试验材料,对其进行水分胁迫处理,分别于浇水后的第2、7、12、17天测定幼苗叶片水分参数及生理指标的变化情况。[结果]随着水分胁迫程度的增大,黄连木幼苗叶片的水势从0.83Mpa降至4.25Mpa,相对含水量从93.7%降至67.0%,水分饱和亏缺从6.3%增加到33.3%,质膜透性从9.2%增加到28.0%,超氧化物歧化酶活性增加了160.8%。轻度胁迫条件下,幼苗叶片丙二醛含量上升,随着胁迫程度的加剧丙二醛含量逐渐下降。脯氨酸含量随胁迫时间的延长呈先减小后增加再减小的趋势。[结论]随着水分胁迫程度的增加,黄连木叶片水分饱和亏缺增加,膜系统受到破坏,保护酶系统活性提高。

[Objective] The aim was to learn about the changes of physiological characteristics of Pistacia chinesis Bunge seedlings under water stress.[Method] With 1-year old potted seedlings of P.chinesis as tested materials,they were treated with water stress and the changes of water parameters and physiological indexes of their leaves were determined on the 2nd,7th,12th and 17th day since watering.[Result] As the water stress degree was increased,the water potential in the leaves of P.chinesis seedlings was decreased from 0.83 Mpa to 4.25 Mpa,their relative water content was decreased from 93.7% to 67.0%,their water saturation deficit was increased from 6.3% to 33.3%,their plasmic membrane permeability was increased from 9.2% to 28.0% and their superoxide dismutase activity was increased by 160.8%.Under light stress,the malonaldehyde contents in leaves of P.chinesis seedlings were increased.As the water stress degree was increased,their malonaldehyde contents were decreased gradually.As the water stress time was prolonged,their cystine contents showed the trend of ＂reducing-increasing-reducing＂.[Conclusion] As the water stress degree was increased,the water saturation deficit of P.chinesis leaves was increased,their membrane system was destroyed and their protective enzyme activity was increased.