在不同土壤水分条件下,对中国沙棘雌雄株叶片的形态结构以及生理生化特征进行了研究.结果表明:在土壤水分条件较差时,中国沙棘雌雄株的叶片结构旱化特征较明显,并且雌株的叶片厚度、上下表皮厚度、侧脉维管束距离均较小,而下表皮毛厚度、密度和栅栏组织与海绵组织的比值均较大,表现出较强的干旱适应性和生态可塑性;雌雄株叶片的游离脯氨酸、可溶性糖和丙二醛含量升高,其中雌株叶片的游离脯氨酸和可溶性糖含量上升幅度大于雄株,而雄株叶片的丙二醛含量上升幅度明显大于雌株.随着土壤水分条件的改变,雌雄株叶片的超氧化物歧化酶和过氧化氢酶活性变化较大.在干旱胁迫下,中国沙棘雌株的生理生化指标多元隶属度值大于雄株.雌株对干旱胁迫的适应性和生理调节能力更强.
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.