中文摘要：

【目的】基于棉花形态器官形成过程的定量描述,模拟棉花三维生长过程,为虚拟棉作研究提供技术基础。【方法】基于2005-2006年棉花品种、播期、氮素、水分和DPC化控试验,将系统分析方法和数学建模技术应用于棉花植株的形态建成,通过对棉花形态数据的定量分析,构建了棉花形态建成模型,主要包括：主茎叶长宽、主茎叶柄长、主茎节间长粗、果枝叶长宽、果枝叶柄长、果节长粗以及棉铃高度和直径等模型。结合OpenGL技术,在Visual C＋＋6.0平台上实现了棉花虚拟生长系统VGSC（virtual growth system for cotton）。【结果】棉花形态模型采用Logistic方程描述各器官尺寸随GDD（生长度日,℃·d）、氮素、水分及DPC的动态变化过程,利用2006年的试验数据对模型进行检验,棉花主茎叶长宽、主茎叶柄长、主茎节间长粗、果枝叶长宽、果枝叶柄长、果节长粗以及棉铃高度和直径的观测值与模拟值的根均方差分别为0.85、0.82、0.87、0.57、0.086、0.65、0.74、0.8、0.73、0.016、0.36和0.4cm,模型预测性好。此外,以NURBS（non-uniform rational B-spline,非均匀有理B样条）曲面模拟棉花叶片及棉铃形状,以圆柱体实现茎（节）可视化表达,构建的虚拟生长系统主要包括模型库、数据库和人机界面。【结论】用户输入系统所需的相关参数值,就可较好地模拟显示棉花器官、个体和群体的三维动态生长过程。

英文摘要：

[Objective] Modeling dynamics of each organ size in cotton growth process, then a virtual growth system for cotton was implemented to provide a technical basis for research of virtual farming. [Method] Based on the potted plant research of cotton variety, sowing date, nitrogen, water and DPC in a summer seasons of 2005 and 2006, with the systematic analysis principle and mathematical modeling technique applied to cotton morphogenesis, a morphological model, which includes several sub-models of leaf, stem, boll, and so on, was developed by the quantitative analyses of experimental data. And a virtual growth system for cotton was implemented with usage of OpenGL for 3D graphic and MFC for graphical user interface. [Result] The results showed that the dynamic change of each organ size could be characterized by logistic equation in relation to GDD, nitrogen, water and DPC. The model was validated by the data from 2006, and the mean RMSEs were 0.85, 0.82, 0.87, 0.57, 0.086, 0.65, 0.74, 0.8, 0.73, 0. 016, 0.36 and 0.4 cm for main stem leaf length and width, main stem leaf stalk length, main stem intemode length and diameter, fruiting branch leaf length and width, fruiting branch leaf stalk length, fruiting node length and diameter, and boll length and width, respectively. Then NURBS was applied to simulate the shape of cotton leaf and boll, internode and petiole were treated as cylinder.Finally, a cotton growth system which comprises of models, database and interface was implemented with OpenGL on the platform of Microsoft Visual C＋＋ 6.0. [ Conclusion ] The system can be used to simulate the real growth process of each organ, individual and group with some inputs.