【作者】 展志岗；

【导师】 王一鸣；

【作者基本信息】 中国农业大学 ， 农业电气化与自动化， 2001， 博士

【副题名】以Corner型植物为例

【摘要】 植物生长模拟模型是定量化研究植物的生长规律的重要手段，涉及到植物学、农学、林学、应用数学、物理学和计算机信息科学等多学科领域。传统的基于生理生态过程的作物生长模拟模型对植物的形态结构的处理过于简化，对植物的结构与生理生态功能的相互作用考虑较少。Corner型植物结构简单，但是其生长过程遵从一般的植物生物学原理，并且许多常见的经济作物属于此类。一些复杂结构的植物可以被看成Corner型植物结构的集合。本文从植物个体和器官的宏观角度，以Corner型植物为对象，研究了一种植物生长的结构-功能模型，分析了模型的数学行为，并依据实验数据对模型进行了参数校准。1．依据植物生物学的基本原理，以生长单元周期为观察时间尺度，以植物器官的鲜质量和几何特征作为模型变量，建立了一种植物生长的机理性的离散时间模型。该模型同时考虑了植物结构与生理功能相互作用，能够并行地模拟植物拓扑结构和几何结构的发展变化。 植物建成的器官数目与环境积温关系密切。本文把这种关系从生长单元周期的角度扩展到有限结构植物的纯粹扩展生长阶段。模型根据植物的水力结构和环境参数计算植物的蒸腾耗水量，由水分利用效率计算生物量产量，依据植物器官的源-汇关系与扩展规律进行生物量的分配，并利用器官的生长规则计算出它们的几何大小。植物拓扑结构和几何结构的生长与变化同时也决定了植物水力结构的变化。这种周期性循环迭代的工作方式把植物生长、结构和功能作用之间的反馈作用有机地结合在一起。这种结构-功能模型在单茎干的棉花、冬小麦、玉米和向日葵等农作物上的应用取得了满意的效果。2．本文研究分析了Corner型植物的结构-功能模型的数学行为，其中模型参数对植物生长与结构的影响规律，为模型的校核提供了有效手段。3．模型中关于植物生物量的分配采用了一种一次性的全局分配方案，把所有器官置于等同的水平上进行考虑，克服了区隔型两级分配方式的缺点，更加适用于模拟植物拓扑结构动态变化的情况。4．用离散型Beta概率密度函数描述植物器官的扩展规律，可灵活地适应多种扩展曲线类型。采用其积分形式产生的S状曲线模拟了冬小麦节间汇强参数的变异性。5．模型参数的校准分两步进行：模型的外部参数，如叶片的厚度等几何造型参数，可由实验测量数据直接确定，而模型的功能参数属于内部隐含参数，必须采用特殊的优化算法进行估计。本文采用非线性最小二乘法估计模型的隐含参数，收敛性好，运算时间少，并提出了对多目标数据实行标准化来自动计算权值的方案。在棉花、冬小麦、玉米和向日葵上的应用实践证明上述方法是有效的。 O ；W 4二博士学位论文 摘要一6．以MsualC－为工具，采用面向对象的程序设计方法，设计完成了集植物生长模拟和分析功能于一体的植物生长模型软件Comeffit．工作于WindowsriNlndotvsNT操作系统下。软件用户界面友好，提供图形、曲线和文本等方式显示植物生物量的生产与分配以及植物结构的动态生长过程，可方便地调整模型隐含参数初值和目标顶目的选择。提出了对植物在生长单元周期内部状态变化进行估计的插值方法。同时，编制了植物器官的平面造型软 ＿＿＿＿。，。＿。。＿＿．、．。。…＿，＿＿．＿…．、、…。＿，。＿＿。＿——件PatZ，与Corneffit软件配合使用。上述软件已经在中国农业大学、中法联合实验室－ （u AMAMA）和法国农艺研究国际合作发展中心（口RA D）等单位应用于科研和教学工作。更多还原

【Abstract】 Plant growth simulation model provides a quantitative approach to plant growth study, which involves multidisciplinary expertise: botany, agronomy, silvics, applied mathematics, physics, computer science and so on. In the traditional ecophysiological process-based models plant architecture is oversimplified, and the interactions between plant structure and functioning are not considered enough. Corner-Model plant is simple from an architectural point of view, but its growth obeys the general laws of plant biology. In fact many economic crops belong to this model and some kind of plants of complex architecture can be seen as the stack of Corner-Model structures. In the dissertation, a structure-function model of plant growth was studied, in which Corner-Model plant was taken as the studied object at the level of individual plant and organs. The mathematical behaviors of the model were analyzed, and the calibration of the model was made using the experimental data of plant growth and structure.1. According to the general laws of plant biology, a mechanistic structure-function model of plant growth at the growth cycle level was made in which organs?fresh weights and their geometric sizes were taken as the model variables. This model took into account the interaction between plant structure and physiological functioning and it was able to simulate the development of both topological and geometrical structure at the same time.The organs production has a strong correlation with the accumulated temperature. In the dissertation, this relationship was extended to the pure expansion stage for those plants that have only finite structural elements. Plant water-transpiration was obtained by the hydraulic structure and environmental parameters~ and the water use efficiency gave the fresh matter production that was shared among organs according to source-sink-based allocation rules and organ expansion laws. Then the geometry of the organs was computed according to their allometric rules. The developments of plant topological and geometrical structure changed the hydraulic structure at the same time. So the model included feed-back processes between plant growth, architecture, and functioning in an iterative and cyclic way. Satisfactory results were obtained on single stemmed cotton plant, winter wheat, maize and sunflower.2.The mathematical behaviors of the model for Corner-Model plant were studied. The results of the influence of the model parameters upon plant growth and structure provided effective means to verify the model.IIIABSTRACT3.A global partition model was adopted for the fresh matter allocation among organs by considering all the individual organs at the same level. It was more suitable for the case that plant topological structure of different kind of organs dynamically changed often. The global model overcame the shortcoming of the compartmental one that worked hierarchically with a primarysecondary sink manner.4.The discrete probability density function of beta distributk,n was used to express the organs?expansion laws, which was flexible enough to fit a variety of expai~ion forms. Its integral form that produced a sigmoid curve was used to simulate the phenomenon thai the internode sink strength varies with internode rank.5.To calibrate the model there were two steps needed: firstly the external parameters could be measured directly or could be obtained by simply processing the experimental data, for example, the thickness of the leaf blade. Secondly some special optimization algorithm had to be used to estimate the functional parameters that were hidden behind the measured data.The nonlinear least squares method was adopted for the estimation of hidden parameters, which had good convergence and took very short computing time. An automatic way to compute data weights for multi-target items by standardization was presented. The methods were practically proved effective by applications to cotton, winter wheat, maize and su更多还原