【作者】 杨亚平；

【导师】 胡景江； 周春菊；

【作者基本信息】 西北农林科技大学 ， 植物学， 2007， 硕士

【摘要】 干旱严重的影响着植物的正常生长发育以及生理代谢,本试验在人工控制条件下,采用溶液培养、PEG6000渗透胁迫处理的方法,研究冷、暖型小麦品种小偃6号(冷型)、陕229(冷型)和NR9405(暖型)在不同水分胁迫条件下,幼苗期小麦叶片中叶绿素含量、可溶性蛋白质含量、细胞膜相对透性、叶片相对含水量(RWC)、水势、SOD、POD、CAT保护酶活性等生理指标的变化规律及叶绿素荧光参数Fv/Fm、Fv/Fo、Fv、Fm、Fo、qP和qNP值的动态变化。主要研究结果如下:(1)轻度(-0.1MPa)、中度(-0.6MPa)和重度(-1.0MPa)水分胁迫条件下,随着胁迫程度的增加,不同水分胁迫梯度对冷、暖型小麦生理特性的影响是:重度〉中度〉轻度水分胁迫。(2)不同水分胁迫条件下,与暖型小麦NR9405相比,冷型小麦小偃6号和陕229叶片中叶绿素和可溶性蛋白质含量相对较高且下降缓慢,丙二醛含量低,累积速度慢,细胞膜相对透性较低,相对含水量(RWC)、水势较高,保护酶系统超氧化物歧化酶,过氧化氢酶,过氧化物酶活性下降幅度小。该结果说明,不同水分胁迫条件下,冷、暖型小麦苗期生理特性差异很大,冷型小麦在干旱胁迫条件下能保持一个相对较优的生理状态,其代谢功能、抗旱能力及对干旱的适应能力较强。(3)不同水分胁迫条件下,冷型小麦幼苗小偃6号和陕229与暖型小麦NR9405相比较,其可变荧光(Fv)、最大荧光(Fm)、可变荧光与最大荧光比(Fv/Fm)、可变荧光与初始荧光比(Fv/Fo)、光化学猝灭系数(qP)降低幅度小,初始荧光(Fo)上升幅度较小,非光化学猝灭系数(qNP)上升幅度较大。该结果说明,不同水分胁迫条件下,冷型小麦光合能力较强,光合系统稳定,这为旱地栽培及抗旱育种提供了参考资料,为冷型小麦性状稳定性提供了充足的理论依据。更多还原

【Abstract】 Drought affected the growth and metabolism of plant seriously .At the artificial controlled condition,the physiological indices of the leaf chlorophyll content, soluble protein content , relative membrane permeability,RWC,hydraulic potential SOD、POD、CAT activities and the dynamic changes of Fv/Fm、Fv/Fo、Fv、Fm、Fo、qP and qNP values of chlorophyll fluorescence parameters were studied between cold type wheat and warm type wheat during seedling period on different water conditions with PEG6000 permeation stress and water solu- tion. The results of the present research are as follows:(1)The effects of differert water stress (-0.1MPa,-0.6MPa,-1MPa) on warm type wheat and cold type wheat physiological indexes were:severe>moderate>light water stress.(2)The cold type wheat had smaller decreases in the chlorophyll content,soluble protein content,SOD、POD、CAT activities, ,lower MDA content, relative membrane permeability,higher water potential, RWC compared with the warm one under different water stress.The results showed the differences of physiological characteristics of cold type wheat and warm type wheat were big .The cold type wheat was superior to the warm type wheat and the cold type wheat adapted to drought better than the warm one.(3)The cold type wheat had smaller decreases in the ratio of the variable to maximum fluorescence(Fv/Fm)、the ratio of the variable to minimal fluorescence(Fv/Fo)、variable fluorescence(Fv)、maximum fluorescence(Fm)、the photochemical quenching coefficient(qP) values, smaller increases of the minimal fluorescence(Fo)value, higher non-photochemical quenching coefficient(qNP)value. The results showed photosynthetic organization of cold type wheat was more stable,photosynthetic ability was more stronger compared with the warm one ,which provided reference data for cultivation and breeding technologies in dryland and also afforded enough theoretical evidence for stability of cold type wheat traits.更多还原