【作者】 梁静；

【导师】 魏学智；

【作者基本信息】 山西师范大学 ， 植物学， 2010， 硕士

【摘要】 酸枣(Ziziphus jujuba var.spinosa)分布广、适应性强、极耐旱,是研究植物响应干旱气候的优良试验材料。通过覆膜技术控制酸枣根系附近土壤水分含量,研究了不同土壤水分条件对酸枣叶片叶绿素含量、组织含水量、可溶性糖含量、丙二醛、保护酶SOD、CAT等生理生化指标的影响,以期探明酸枣适应干旱的生理机制。从而进一步丰富酸枣资源抗旱性的评价内容。为酸枣的抗旱栽培、育种和品种的区域化提供科学的依据。结果显示:1.不同程度土壤干旱对酸枣叶绿素含量的影响,对照组与处理组呈现相似的变化规律,表现为:实验前期,土壤水分逐渐减少时,酸枣叶片的叶绿素含量缓慢下降;实验中期,随着土壤含水量的变化,叶片叶绿素含量变化表现出一种假象的复水效应,呈上升趋势,随后逐渐下降;至末期叶片仍保持较高的叶绿素持有率。2.酸枣在土壤含水量为6%左右时,叶片仍能分别维持在80%左右的相对含水量和63%左右的绝对含水量。自然饱和亏也保持在20%的较低水平,较其他旱生植物的低,说明酸枣具有较强的抗旱能力。3.持续干旱导致处理组酸枣叶渗透势、水势呈“W”型下降趋势,对照组变化趋势相似。酸枣的水势和渗透势很小,处理组酸枣叶片水势和渗透势在实验期间分别维持在-0.63Mpa、-0.13 Mpa水平。4.酸枣叶片中的游离脯氨酸含量随处理时间的延长与可溶性糖含量变化趋势相同,处理组较对照组的平均增幅分别为1.3、1.2倍。渗透调节物质可溶性糖、脯氨酸的累积均能降低渗透势,维持生长,使酸枣具备了低水势抗旱的特征。5.土壤含水量对酸枣膜伤害和保护酶活性的影响,结果表明,实验前期,随着土壤含水量的下降,细胞膜受到伤害,细胞膜透性增加,电导率随之增强,作为膜脂过氧化产物的MDA含量增加,随着保护酶活性的加强,膜脂过氧化程度下降,实验中期,MDA含量和电导率都大幅下降,至实验后期,保护酶活性下降,导致活性氧积累增加,使得膜脂过氧化作用加重,MDA含量升高,膜透性增大。6.随着处理时间的延长,处理组酸枣叶片保护酶SOD、POD、CAT的活性都表现出先升后降的变化趋势,但仍然高于对照组。7.随着干旱程度的加剧和处理时间的延长,处理组酸枣叶片硝酸还原酶活性表现出先降低后升高,又降低的变化趋势。更多还原

【Abstract】 Ziziphus jujuba var.spinosa is a excellent testing materials to study plant responses to drought which widely distributed, strong adaptability, very drought-tolerant. In order to show physiological mechanisms of adaptability to drought of Ziziphus jujuba var.spinosa ,we examined the effects of different soil moisture on the content of chlorophyll ,leaf water, soluble sugar, MDA, SOD, CATand other physiological and biochemical indices through the coating technology for the control of soil moisture content near its root system.Then the evaluating content of droght-resisitance was enriched further.It could offer scientific evidence for breeding, culture of droght-resisitance and culture in different area of Ziziphus jujuba var.spinosa.Results showed that:1. The date indicated that the content of chlorophyⅡunder different soil drought. With the reduction of soil moisture,the content of chlorophyⅡreduced slowly; then, with the changes in soil moisture,the content of chlorophyⅡin leaves showed a illusion of re-water effect, an upward trend, and then gradually reduced; to the end of leaves reminded at a high rate of chlorophyⅡhold.2. When soil water content of Ziziphus jujuba var.spinosa at 6%,the relative water content and absolute water content of Ziziphus jujuba var.spinosa keep at 80% and 63%yet. While natural water saturation deficit still maintained at a low level,Lower than any other dry plants, indicating Ziziphus jujuba var.spinosa has a strong drought resistance.3. Continuing drought lead Ziziphus jujuba var.spinosa leaf osmotic potential, water potential was "W"-type downward trend of treatment group,as well as control group. Ziziphus jujuba var.spinosa has small water potential and osmotic potential.The water potential and osmotic potential of treatment group during the experiment were maintained at -0.63Mpa,-0.13Mpa level.4. The changes of the content of free proline and soluble sugar with the extension of processing time has the same trend. compared with control, treatment group was 1.3、1.2 times the average. Osmotic and adjustive matter,for example:soluble sugar content and proline content increased can reduce the osmotic potential to maintain growth, so that Ziziphus jujuba var.spinosa with a low water potential and drought characteristics.5. Soil moisture on membrane injuried and activity of enzyme in Ziziphus jujuba var.spinosa leaves. Results showed that with the decline in soil water content, cell membrane injury, cell membrane permeability increases, conductivity increases, and MDA were increased, with the strengthening of activity of protective enzymes, membrane lipid peroxidation decreased, then, MDA content and electrical conductivity declined sharply, to the late experiments, protective enzyme activity is reduced, leading to increased accumulation of reactive oxygen species, making film increased lipid peroxidation, MDA content increased, membrane permeability increased.6. With the extension of processing time, Ziziphus jujuba var.spinosa showed the variation tendency of falling after rising ,such as SOD、POD、CAT, but the change laws of three kinds of enzymes were different to some extent.7. As the degree of drought stress intensified and time of drought stress prolonged to restrain more water, activity of NRA in Ziziphus jujuba var.spinosa leaves of treatment group showed the variation tendency of falling after rising , then falling.更多还原