目的 通过对猴耳环种子萌发进行人工水分胁迫处理，探讨其对种子萌发过程中生理生化指标的影响。方法 分别采用5%、10%、15%、20%聚乙二醇6000（PEG）处理猴耳环种子，测定种子的发芽率、平均发芽速度、发芽指数及萌发过程中细胞膜透性、脯氨酸量、可溶性蛋白量、丙二醛（MDA）量、超氧化物歧化酶（SOD）和过氧化物酶（POD）活性的动态变化。结果 随着PEG胁迫强度的增加，种子萌发受到明显抑制，发芽率、发芽指数显著降低，提高了平均发芽速度；萌发期间各生理指标均高于对照，细胞膜透性、脯氨酸、MDA量呈上升趋势，可溶性蛋白量呈下降趋势，SOD、POD活性均不同程度地表现为先上升后下降的趋势。结论 猴耳环在轻度水分胁迫时，具有一定的耐旱性。

Objective By the treatment of artificial water stress on seed germination of Pithecellobium clypearia to explore the physiological characteristics during seed germination. Methods The seeds of P. clypearia were treated with 5%, 10%, 15% and 20% PEG 6000, then the seed germination rate, mean germination speed, germination index, cell permeability, proline (Pro), soluble protein, content of malondialdehyde (MDA), and activities of superoxide dismutase (SOD) and peroxidase (POD) were measured. Results With the increase of PEG stress intensity, the germination rate and germination index were decreased, and the mean germination speed was increased. The cell permeability, Pro, and MDA showed increasing trends, while soluble protein showed decreasing trend. The activities of SOD and POD presented rising tendency then followed by decreasing. Conclusion Under the light water stress, P.clypearia has ability to resist drought stress.