Simulation Of Phtotoassimilates Partitioning In Vegetative Growth Of Winter Wheat In Response To Environmental Factors

Modelling technology, as a powerful research tool, has played a key role in researching complex systems or processes. Crop growth models have already made great progresses in past decades. But the researches on photoassimilates partitioning, specially partitioning model, are still a weakness. Exist photoassimialtes partitioning models have some un-overcome insufficiency. Experiential models do not have physiological aspects and are not able to react with environments. Mechanical models need complex parameters such as substrate concentration, organs activities and so on, which can't be obtained in modeling, so their applications are very limited. Environmental factors have important influences on photoassimilates partitioning. There is an undoubtedly necessary to develop a partitioning model that can response with environmental factors in perfecting and improving the function of crop growth models.This paper developed a process-based photoassimilates partition model (PPModel) that could response with environmental factors.1. Based on the theory of function equilibrium relation, PPModel integrates the processes of photosynthesis and the partitioning of photoassimilates to plant organs for growth and dry matter accumulation, linking leaf transpiration and root absorption according to the water balance in the plant-body. PPModel includes four sub-models: photosynthesis sub-model, transpiration sub-model, absorption sub-model and photoassimilates partitioning sub-model. Every sub-model is feasible and accurate in predicting the corresponding physiological process. So PPModel not only has a good capacity to predict the whole plant biomass accumulation but also the detailed physiological processes such as leaf photosynthesis, transpiration and root absorption.2. To a given crop species, it is mainly determined by environmental factors forphotosynthesis, transpiration, absorption and photoassimilates partitioning. PPModel was just driven by environmental factors. So the PPModel can response to environmental factors and can reflect the dynamics of photosynthesis, transpiration, absorption and biomass partitioning under various environmental factors.3. Using the two year trial data to validate the PPModel, it is showed that the simulations agreed well with the observation. Simulated evaportranspiration is very closed related to Lysimeter value. Simulated leaf, stem biomass agreed well with the observed values.