干旱胁迫下文冠果幼苗叶片的生理响应

Physiological Responses of Xanthoceras sorbifolia Seedling Leaves under Soil Drought Stress

以文冠果(Xanthoceras sorbifolia)1年生幼苗为材料,通过试验生态学的方法,按土壤绝对含水量13%、18%和25%3个水分梯度对文冠果盆栽幼苗进行水分胁迫30d后,测定文冠果幼苗叶片中游离脯氨酸含量、丙二醛含量和细胞膜相对透性等生理指标。结果表明,在适宜土壤含水量、轻度干旱胁迫和重度干旱胁迫条件下,文冠果叶片中游离脯氨酸含量、丙二醛含量和细胞膜透性差异显著。随着干旱胁迫程度的增加,文冠果幼苗叶片中游离脯氨酸、丙二醛含量显著增加,细胞膜相对透性大幅度增加。在土壤干旱胁迫下文冠果幼苗叶片通过增大细胞膜透性、增加体内脯氨酸含量来提高自身的抗旱能力。土壤干旱胁迫程度越严重,文冠果幼苗叶片细胞膜脂过氧化和脱氧化程度越高。文冠果具有较强的耐旱能力,可以在干旱和半干旱地区推广栽培。

In order to provide a theoretical basis for plantation of Xanthoceras sorbifolia in arid and semi-arid areas and to understand it＇s mechanism of drought-tolerance,the physiological responses of X.sorbifolia pot seedling leaves under soil drought stress were investigated by using one-year-old seedlings.The content of free proline,malondialdehyde and cell membrane permeability in leaves under three different soil content levels（13%,18% and 25%） were measured while maintaining 30 d soil drought stress in greenhouse.Significant differences were observed in the contents of free proline,malondialdehyde and the cell membrane relative penetrability among the three drought stress levels in the leaves.Compared to 25% content of soil water,the content of free proline,malondialdehyde and the cell membrane relative penetrability were higher than those of 13% and 18% water levels.With the increase of drought stress,all the three indices increased.Some physiological responses would appear when X.Sorbifolia pot seedlings suffered from thirty days soil water stress.Under the condition of drought stress,the content of proline and the cell membrane permeability of each leaf increased to improve its drought tolerance.Meanwhile,the more serious drought stress was the higher degree of lipid per-oxidation and de-oxidation occurred.