Dynamic simulation of stem, leaf and pod development on soybean

Abstract: Based on systematic observation, the organ morphogenesis model was established on soybeans. In the model, the time step was physiological development time, the growth process and the growth of the order of the stem, leaves and pods were measured by physiological development day, the model parameters were determined by genetic parameters, and the minimum nitrogen content, maximum nitrogen content, and critical nitrogen content were used to express the impact of nitrogen. In the model, internode potential length and potential thickness increased gradually with the increase of the number of soybeans internode, and reached a maximum at the ninth and seventh internode, and then decreased gradually. Therefore, the potential length of the ninth internode and potential thickness of the seventh internode were determined as potential genetic parameters that can calculate the other internodes' potential length and potential thickness. Because of similar leaf morphology on each internode on soybeans, this study only modeled the dynamic of the third fronds. Based on soybean morphological characteristics, this study simulated the pods which first appeared on the third internode. The results showed that the absolute prediction errors ranges of internode length, internode thickness, leaf length, leaf width, pod length, pod width, and pod thickness were 0.08-0.59, 0-0.10, 0.28-0.58, 0.31-0.39, 0.14-0.39, 0.09-0.21, 0.04-0.09 cm respectively with the root mean square errors (RMSE) being 0.25-0.28, 0.04-0.05, 0.47, 0.35-0.36, 0.24-0.39, 0.14-0.17, 0.06-0.07 cm, respectively. The model reflected a satisfactory prediction. Moisture had a greater impact on soybean organ morphogenesis. Because of the test conditions, this study did not establish a moisture influence factor model. The model establishment of water and nitrogen coupling soybean organ morphogenesis is the next research program. The models also need to be tested at a greater variety and a wider geographical scope.