夏玉米叶片含水量变化及其对光合作用的影响

发布时间：2018-04-14 05:11

本文选题：夏玉米 + 土壤水分胁迫　；参考：《中国气象科学研究院》2017年硕士论文

【摘要】：叶片是光合作用的重要器官,其含水量的变化必将影响光合作用,同时叶片含水量是大气干燥度、土壤供水能力和作物耐旱能力综合作用的体现。研究叶片含水量变化及其对光合作用的影响可为进一步提高光合作用模拟的准确性和客观辨识夏玉米干旱的发生发展及监测预警提供参考。本论文以2014年6-10月在中国气象科学研究院固城生态与农业气象试验站开展的夏玉米三叶期6个水分梯度持续干旱模拟试验资料为基础,分析不同土壤水分胁迫强度、持续时间及不同生育期下夏玉米叶片含水量变化及其与叶片净光合速率的关系。主要研究结果如下:(1)叶片含水量对土壤水分变化存在阈值响应,在受到一定程度土壤水分胁迫后,叶片含水量开始显著下降。土壤水分胁迫强度影响叶片含水量的下降速率,土壤水分胁迫程度越重,叶片含水量下降速率越大;土壤水分胁迫持续时间增加降低叶片含水量,减小处理间差异;不同生育期的夏玉米叶片含水量随土壤相对湿度的变化速率不同,叶片含水量下降速率变化次序为拔节期三叶期七叶期。夏玉米叶片含水量的变化与土壤相对湿度呈非直角双曲线关系,叶片最大含水量为85.14%。(2)指出叶片含水量是影响夏玉米叶片净光合速率的重要因子,且叶片净光合速率与一定范围内的叶片含水量呈显著的二次曲线关系,过高或过低的叶片含水量将导致二次曲线关系不显著。(3)夏玉米叶片净光合速率为零时的叶片含水量随土壤水分胁迫程度的加剧总体呈减小趋势;随土壤水分胁迫持续时间的增加呈先减小后增加趋势;不同生育期的夏玉米叶片光合作用为零的叶片含水量存在差异,呈现为三叶期拔节期七叶期。平均而言,当叶片含水量减小到70.30%时,叶片净光合速率为零。(4)发展完善了包含叶片含水量影响的C4植物Rubisco酶活性限制光合作用生化机理模型。
[Abstract]:Leaf is an important organ of photosynthesis, and the change of water content of leaf will affect photosynthesis. Meanwhile, the water content of leaf is the comprehensive function of atmospheric dryness, soil water supply ability and drought tolerance ability of crops.The study of leaf water content change and its effect on photosynthesis can provide a reference for further improving the accuracy of photosynthesis simulation and objectively identifying the occurrence and development of summer maize drought and monitoring and early warning.Based on the simulated data of 6 water gradients of summer maize at Gucheng Ecological and Agrometeorological Experimental Station of Chinese Academy of Meteorological Sciences from June to October 2014, this paper analyzed the different soil water stress intensity.The relationship between leaf water content and net photosynthetic rate of summer maize at different growth stages.The main results were as follows: (1) there was a threshold response of leaf water content to soil moisture change, and the leaf water content began to decrease significantly after a certain degree of soil water stress.The intensity of soil water stress affected the decreasing rate of leaf water content, the more serious the soil water stress, the greater the decline rate of leaf water content, the longer the duration of soil water stress, the lower the leaf water content and the difference between treatments.The variation rate of water content in summer maize leaves with soil relative humidity was different at different growth stages, and the decreasing rate of leaf water content was in the order of jointing three-leaf stage and seven-leaf stage.The relationship between leaf water content and soil relative humidity was non-right hyperbolic, and the maximum leaf water content was 85.14%, which indicated that leaf water content was an important factor affecting the net photosynthetic rate of summer maize leaves.The relationship between leaf net photosynthetic rate and leaf water content in a certain range was significantly conic.Too high or too low leaf water content will cause the quadratic curve relationship is not significant.) the leaf water content with 00:00 net photosynthetic rate of summer maize leaves decreases with the increase of soil water stress.With the increase of the duration of soil water stress, it decreased first and then increased, and the leaf water content of summer maize leaves with zero photosynthesis at different growth stages was different, which appeared to be the seventh leaf stage at jointing stage.On average, when the leaf water content decreased to 70.30, the net photosynthetic rate of leaves was zero. 4) the biochemical mechanism model of Rubisco activity restriction photosynthesis in C4 plants with the effect of leaf water content was improved.
【学位授予单位】：中国气象科学研究院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S513

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