Abstract: A field experiment was conducted to study the leaf morphological structure and physiological and biochemical characteristics of female and male Hippophae rhamnoides subsp. sinensis under  different soil moisture condition. When the soil moisture condition was poorer, the leaf structure of the plants displayed distinct xeromorphic characteristics, being more obvious for the female plants. Comparing with those of male plants, the leaf thickness, thickness of upper and lower epidermis, and the distance between lateral vein bundles of female plants were smaller, while the thickness and density of lower epidermis hairs and the ratio of palisade tissue thickness to sponge tissue thickness were in adverse, indicating that female plants had stronger drought adaptability and greater ecological plasticity. With the decrease of soil moisture content, the leaf dissociative proline, dissoluble sugar, and malonaldehyde (MDA) contents of both male and female plants all increased, but for female plants, the increment of their leaf dissociative proline and dissoluble sugar contents was larger, while that of MDA content was smaller than the male plants. With the changes of soil moisture content, the leaf superoxide dismutase  and catalase  activities of the plants varied greatly, but had no regular pattern. Under the stress of soil drought, the values of multivariate membership function of test parameters were larger for the female than the male plants, suggesting that the female plants of H. rhamnoides subsp. sinensis had stronger physiological regulation capability and greater adaptability to drought stress.

Key words: Hippophae rhamnoides subsp. sinensis, female and male plants, leaf, morphological structure, physiological and biochemical characteristics, spacing, full heading stage, canopy structure, extinction coefficient, photosynthetic characteristics, yield.