【作者】 李茂松；

【导师】 王道龙；

【作者基本信息】 中国农业科学院 ， 作物生态学， 2010， 博士

【摘要】 水资源短缺已经成为农业可持续发展的严重障碍,蒸腾失水是农作物水分消耗最主要的部分。为此,开展农作物蒸腾及其调控研究,确定水分胁迫和抑制蒸腾剂使用条件下作物蒸腾水分消耗及其抑制的机理,明确奢侈蒸腾调控的理论基础,开展奢侈蒸腾及其调控的理论基础进行研究,探明合理抑制作物奢侈蒸腾的途径,从而为抗旱减灾及提高水分利用效率等提理论基础和技术支撑。本研究开展了水分胁迫对不同时期大豆和小麦的生理生态指标的影响研究、抑制蒸腾后大豆和小麦的生理生态反应特征和产量变化、不同水分梯度条件下作物在不同的抑制蒸腾措施下的不同反应等实验,在奢侈蒸腾及其调控方面进行了系统的实验研究。取得主要的研究成果如下:1、大豆和冬小麦均存在奢侈蒸腾。通过试验测定分析表明,气孔是蒸腾失水的唯一路径,水分胁迫下,大豆苗期叶片含水量及叶绿素a、叶绿素b含量在干旱处理前期增加,随着干旱胁迫时间的延长或干旱程度加重,叶绿素的含量呈现下降趋势;干旱胁迫下,苗期叶片的光合速率(Pn)、气孔导度(Gs)、二氧化碳同化速率(Ci)均降低。蒸腾速率的日变化趋势与气孔导度的日变化趋势基本一致,灌溉量减少导致土壤含水量减少,气孔导度减小,蒸腾速率快速下降,CO2的吸收受阻因而导致光合速率降低。2、轻度水分胁迫条件下大豆和小麦叶片的光合能力、蒸腾能力和气孔导度均增强,细胞内部CO2同化能力也增强,轻度的水分胁迫能提高大豆和小麦的抗逆能力,并且这种对胁迫环境的适应随着生育进程的推进而增强。轻度水分胁迫下,叶温低于气温,在重度水分胁迫下,叶温高于气温。无干旱胁迫下使用抑制蒸腾剂,大豆和小麦的蒸腾速率和气孔导度增强,促进增产,增产幅度为11.8%~39.5%。其中,增加光合产物向籽粒输送比例是增产的主要原因。3不同水分梯度试验结果表明,大豆和小麦叶片的气孔导度随着水分胁迫的增强而增加,随着胁迫时间的延长增加幅度更明显,随着水分胁迫的增强气孔变得更小,干旱胁迫对气孔开张面积日变化影响较大。4.在无干旱条件下,使用抑制蒸腾剂能够减小大豆和小麦的气孔导度、增强光合能力和蒸腾能力,提高大豆和小麦产量。轻微水分胁迫条件下使用蒸腾抑制剂得到了相似结果,但干物质分配比例中,籽粒部分的比重大于无水分胁迫。5.抑制蒸腾剂在充足水分条件下促进小麦的光合能力、蒸腾能力和气孔导度,而在干旱条件下则能起到抑制蒸腾、保水和提高水分利用效率的作用。抑制奢侈蒸腾在生产实际中,可以达到有灾抗灾、无灾增产的效果。更多还原

【Abstract】 Water resources shortage strongly restricts sustainable development in China.Water loss through transpiration is the main path. This study was focus on the crop transpiration and it’s control, to determing the mechanism and theory of water consumption through transpiration under water stress condition using anti-transpirate. Does the luxury transpiration occur in crops? Could the luxury transpiration be reduced? How the anti-transpirants--kinds of chemical materials restraining the transpiration from crop leaves, reduce the tranpriation and its possible mechanism. Thus, few experiments were designed for this study, including: the changes of eco-physiological characteristics and yield in soybean and winter wheat under different water stress conditions, the changes in photosynthetic rate, stomatal conductivity, transpiration rate of soybean and wheat under non-water stress conditions with anti-transpirants, and the performances of eco-physiological characteristics when transpiration was restrained by two kinds of anti-tranpirants (Stomatal Closing and film Forming) on winter wheat. The main results from this research are following:1. When soil water stress level is slight, leaves showed higher abilities in photosynthesis, transpiration, stomatal conductivity and CO2 assimilation as compared with non-stress condition in soybean and wheat, indicating that the slight stress condition could induce its own ability in adapting the changed environment. Experemental results show that luxury transpiration exist in soybean and winter wheat. Stomata as the only chunnel, under water stress condition, the daily variation of transpiration rate and stomata conductivity nearly keep the synchronization, reduce irrigation lead to siol moisture decrease, and reduce the stomata conductivity,transpiration rate decreased sharply,furthermore, CO2 absorbtion constrained also leads to the photosynthesis rate decreased rapidly. The concentration of conchlorophyll a and b increased before water stress in the soybean seedling stage,but there have decreased as the water stress duration extended and the water stress Severity aggravated. Moreover, under the water stress, the soybean leaves photosynthesis rate(Pn), stomata conductivity(Gs), CO2 absorbtion rate(Ci) were decreased in the seedling stage, under the slightly water stress condition, the leaf’s surface temperature lower than air temperature, but under extremely water stress condition, the leaf’s surface temperature higher than air temperature.2. The soybean and winter wheat photosynthesis rate, transpiration rate, stomata conductivity were increased under slight water stress, CO2 absorbtion rate(Ci) were increased also, thus means slight water stress can improve drought tolerance ability in soybean and winter wheat As water stress become stronger and advanced, the stomatal density of soybean and wheat leaves increases, moreover, the stomata becomes smaller and the aperture area changes severely under stress conditions.3. When the leaf transpiration in soybean and wheat is restrained with anti-transpirants under non-stress condition, the photosynthesis rate, transpiration rate and stomatal conductivity increase. The response mechanism maybe the same as those under slight stress conditions, indicating that the transpiration restrained method may help in increasing yielding ability when no water stress occurred.4. When leaf transpiration is restrained, the characteristics, including the photosynthesis ability, the transpiration ability and stomatal conductivity, were accelerated under non-stress condition, on the contrary, were reduced under stress conditions. Thus, the transpiration restraining methods could help in maintaining water inside the crops and increasing the water use efficiency.5. The results showed that the luxury transpiration occurs and its suppression could make it possible, that is: reducing the loss when stress occurs while promoting the yielding when non stress.更多还原