Study On Virtual Plant Technology Based On Plant Growth Model

It is a key issue for constructing virtual plant model conforming to the developmental rule of botany to consider simultaneously the change of morphology and physiology,which can also extend the application area in modern agriculture production.The dissertation develops the growth simulation model of dominant plant reed in beigu mountain after doing lots of experiments,and the corresponding virtual plant simulation model as well as its visual model are also founded.Through developing a virtual plant growth simulation system with parameters,it can perform the simulation of reed growth process with various parameters,which will offer theoretic and technologic bases in analyzing or predicting the wetland reed developmental conditions with visualization method.The main research works in the paper are as follows:1. Introducing a consulting model of structure and function for virtual plant growth. According to the construction method of functional-structural model of virtual plant, the author proposes a consulting model of structure and function for virtual plant growth,and elaborates the change of morphological topology architecture of virtual plant growth quantitively based on the plant morphological architecture and its growing law.2. Constructing the developmental simulation model of reed.After analyzing the natural conditions of beigu mountain wetland and the developmental characteristics of its dominant plant reed,it constructs the developmental simulation model of reed with the method of growing degree day,and the growing degree day parameters are also calculated in every developmental stage.3. Studying the morphological and physiological simulation model. For morphological architecture model,it constructs the dynamic model of reed stem change and internode number change as well as leaf area index change;For physiological function model,it constructs the dynamic model of reed photosynthesis,and the reed dry matter allocation model is founded using allocating index method,which can replace allocating coefficient method that usually causes much variation in constructing dry matter allocation model under different water fertilization condition or various experimental specimen,the model is also demonstrated better explanation and prediction in the dynamic simulation of dry matter allocation.Additionally,it simulates the growth of man-planted reed in the paper,and compares the developmental process of man-planted reed with that of the crude reed.4. Constructing virtual plant simulation model of reed based on growth mechanism.On the assumption of reed morphological architecture and physiological characteristics,the author offers some concepts such as organ acquiring strength,organ expansion distribution rate and expansion distribution function,first-allocation and second-allocation of assimilate.The correlationship between plant topology architecture and accumulative growing degree day is founded. On the basis of the existing allocation theory of assimilate,the way of second-allocation of assimilate is introduced,and the corresponding relationship between the organ acquiring strength and the allocating index of dry matter is also constructed.Additionally,the model of dry matter acquired by the same organs at different places when the plant growth age is i years old,which effectively connects the production with the allocation of assimilateAccording to the character of model parameters, parameters of the expansion distribution rate function of organs are calculated by adopting the least square estimation method of nonlinear function parameter.Based on the presented model of second-allocation of assimilate,models of geometric architecture simulation of organs such as leaf and petiole as well as internode are constructed,and the related parameters are also analyzed or calculated.The presented models are proved to be true and feasible to some extent through the experimental data from the year 2006.5. Studying on the visualization model of virtual plant growth. Based on the constructed virtual plant model,the visualization model of virtual plant growth is founded adopting the visualization technology.The information included in the objects such as leaf,petiole and internode in addition to structural unit is organized effectively in terms of structural object.Furthermore,the algorithm of graphic information of plant topology structure is presented,and the graphic method of structural unit is introduced.6. Constructing the virtual plant growth simulation system which is also applied in practice.The dissertation uses Visual C++ as programming tool,connected with the function of related graphic modules of the open graphic tool library,develops a prototype system with parameters of virtual plant growth.In the end,it predicts and simulates visually the wetland reed growth process using the system,which proves the presented models and related algorithms effective and feasible.In addition,the dissertation analyzes the sensitivity of parameters which can affect the simulated results,the methods through experimental determination of these parameters are also introduced.