【作者】 冯道俊；

【导师】 王宝山； 曹慧；

【作者基本信息】 山东师范大学 ， 植物学， 2006， 硕士

【摘要】 本研究采用盆栽控水的方法,以玉米为试材,研究了不同程度水分胁迫(旱和涝)对玉米幼苗的生长、生理生化指标的影响及机理,比较了旱、涝对玉米幼苗影响的差异,通过对不同程度水分胁迫下玉米幼苗生长、某些生理指标、光合参数、抗氧化酶活性、质膜透性、丙二醛含量的分析,揭示了水分胁迫对玉米苗期光合作用的影响,特别是非气孔因素对光合作用的影响,从而为玉米苗期水分胁迫研究提供一定的参考,为进一步开展玉米的抗旱和抗涝性研究打下一定的基础。1.本试验测定了不同水分胁迫处理玉米幼苗的株高、茎粗、叶面积、地上部分干重、根条数、根干重、根干重与地上部分干重比(根冠比)等7个性状,结果表明:重度干旱胁迫和水涝胁迫对植物的生长(地上部分和根部)均起到抑制作用,但抑制的程度有所不同。初期,干旱可促进根系的生长,水涝可促进茎叶的生长。随胁迫时间的延长,重度干旱和水涝对玉米幼苗的生长都起到极大的抑制作用,玉米幼苗的生长几乎停滞。2.本试验测定了不同水分胁迫处理对玉米幼苗某些生理指标(叶片相对含水量、根系活力、叶绿素含量、可溶性蛋白质和脯氨酸含量)的影响,结果表明:重度干旱和水涝胁迫情况下,叶片相对含水量、根系活力、叶绿素含量、可溶性蛋白质含量随胁迫时间的延长逐渐降低,脯氨酸含量迅速增加。水涝初期,叶片相对含水量影响较小,随着胁迫时间的延长,叶片相对含水量降低,但降低的幅度大大小于干旱胁迫同期的影响;短期旱、涝时,玉米幼苗根系活力均升高,随胁迫时间的延长根系活力迅速降低,但水涝胁迫下玉米幼苗根系活力降低的幅度小于干旱胁迫同期的影响;旱、涝使玉米幼苗叶绿素含量均降低,但干旱的影响要大于水涝;旱、涝对可溶性蛋白质含量的影响差别不大,对脯氨酸含量的影响水涝要稍大于干旱,但幅度不大。3.本试验测定了不同水分胁迫处理对玉米幼苗光合参数(净光合速率、气孔导度、胞间二氧化碳浓度),结果表明:旱、涝胁迫下玉米幼苗净光合更多还原

【Abstract】 In the present study, the effect and mechanism of water stress (drought and flooding) on morphological, physiological and biochemical indexes of maize seedlings were examined using pot culture. Comparison of effect of a drought and flooding stress photosynthesis parameters, the activity of antioxidant enzymes, membrane permeability and the content of MDA on maize seedlings was analyzed. Especially, effect of nonstomatal factors on photosynthesis of maize seedling exposed to drought and flooding stress was investigated. The main results were as follows:1. Seven indexes, including the relative height, stem diameter, leaf area, shoot dry weight, root numbers, root dry weight and root/shoot ratio of maize seedlings exposed to drought and flooding stress were determined. The results showed that serious water stress (drought and flooding) restrained the plant growth (shoot and roots), decreased the relative height, leaf area and stem diameter, and reduced the accumulation of dry weight. However, the inhibition degrees were different as the water stress changed. Drought and flooding stress enhanced the growth of roots and shoot in the early days, respectively. But all the indexes decreased markedly if maize seedlings were exposed to serious drought and flooding stress for a long time and the growth of maize seedlings was almost stopped.2. In this study, physiological indexes, including the relative water content of leaves, root vigour, the chlorophyll content, solubile proteins and proline were measured. The results showed that, under the condition of both drought and flooding, the relative water content of leaves, the root activity, the chlorophyll content, solubile proteins of maize seedlings gradually decreased, but the proline content increased greatly. At the beginning of flooding stress, the water relative content of leaves changed slightly and decreased with time.更多还原