Parallel Simulation Model For Maize Growth By Integrating The Eco-Physiological Function With Morphological Architecture

As one of the widely cultivated crops in the world, maize has been receiving more research attentions in the field of modeling crop eco-physiological processes, owing to its relative simple morphological architectures. Through approaching its morphological architecture, it's known that maize is composed of metamers, while metamers comprise of internodes, nodes and some affiliated organs such as leaves. Therefore, maize growth can be viewed as a process of the metamers' emergence and development.The dissertation developed a parallel simulation model based on the mechanism of feedback between plant morphological architecture and eco-physiological function, the time interval of which is growth cycle (GC) and the architectural unit of which is metamer. The model comprises of several sub-modules: development module, assimilate production module, assimilate partitioning and accumulation module, organ's morphological construction module.The development module performs the predictions of maize growth process based on the linear correlationship between the increase of the number of metamers and the change of accumulative temperature; the assimilate production module estimates the assimilate yield on the basis of linear correlationship between the increase of the net assimilate on maize aboveground part and the change of accumulative evapotranspiration; the assimilate partitioning and accumulation module uses the sink strength P0 (o denote for leaf blade, sheath, internode, female, male) to express the matter acquiring ability of different types of organs, while uses expansion function to express the growth variation of one specific type of organ(assuming that the same type of organs shares with the same growth pattern). The sink strength, multiplied with the expansion rate, is defined as the current matter demand, each organ gain the newly produced assimilate based on the ratio of its current matter demand to the total matter demand; the sum of the assimilate allocated to each organ is the biomass accumulation. The organs' morphological construction module realizes the simulation on the organ's geometric architecture based on the relationship between the fresh weight of leaves, internodes and geometric architecture as well as the organs's accumulation biomass.According to the field experimental data and meteorological data from the year 2000, the development module parameter DR was calculated and its value is 0.0155 C-1 d-1; the assimilate production module parameter WUE is 6.71Kg/m3. The parameters as sink strength and expansion rate of biomass partitioning are difficult to be directly acquired from experiment, but they can be obtained from the CornerFit software and the experimental data of the year 2000. However, the sink strength values extracted from that software are just the mean values spanning the thorough process from seedling to one specific growth cycle of maize, therefore, the dissertation employs the biomass value for each cycle as the weighing factor, in conjunction with the mean sink strength, to calculate the real value of sink strength for each specific growth cycle. The parameterization of organ's morphological constructionincludes the setup of the parameters of leaves as well as internodes. From organ's morphological construction module and the data of year 2000, leaf and internode morphological parameters are obtained, The ratio ?b of fresh blade weight to the area is 0.0284 g/cm2, the fitting coefficient kb, Y between leaf fresh weight and the length are 20.74 and 0.4609 respectively, the fitting coefficient between the leaf sheath area and the product of length and width is 0.7233, The ratio p of fresh leaf weight to the unfolded area is 0.083 g/cm2, The fitting coefficient kp u between the leaf sheath width and fresh weight are 2.7702 and 0.4642 respectively; The internode morphological parameters are be, B, except the anomaly occurred in the eighth internode, the values of B in other internodes are quite similar, while be demonstrates the increasing trend with the elevating posit...