Dynamic simulation of maize main organ morphogenesis

To construct a model of maize morphogenesis during physiological development, the processes of growth and orders of stem, leaves and ears were measured on the basis of the physiological development time (PDT). The model parameters were determined from genetic traits and the minimum, maximum and critical nitrogen contents used to determine the impact of nitrogen on the model performance. The model was tested on 'Jinshan27', 'Xianyu335', 'Weike702' and 'Zhengdan958' maize varieties. The experiment results showed that the internode potential length increased gradually with increasing number of maize internode up till the maximum at eight internodes, and then gradually decreased; while the internode potential thinkness was the largest for the first internode. Therefore the potential genetic parameters were determined at the potential length of the eighth internode, and the potential thinkness of the 1st internode, which was used to calculate the potential lengths and thicknesses of the other internodes. The experiment results indicated the peak values of leaf length and width at the 13th leaf. Therefore, the potential length and width of the 13th leaf were used to determine the potential genetic parameters of leaf. The ear and tassel length and thinkness were also simulated on the basis of PDT under the impacts of nitrogen application. The results under different varieties and test sites showed that the absolute prediction errors ranges of the internode length, internode thickness, leaf length, leaf width, ear length, ear width, tassel length and tassel width were respectively 0- 2.5 cm, 0.001- 0.397 cm, 0- 2.6 cm, 0- 1.5 cm, 0.1- 1.4 cm, 0- 0.255 cm, 0.1- 2.1 cm and 0.001- 0.158 cm. The corresponding root mean square errors (RMSE) were respectively 0.2- 0.8 cm, 0.050- 0.156 cm, 0.5- 1.1 cm, 0.1- 0.5 cm, 0.4- 0.7 cm, 0.070- 0.141 cm, 0.5- 0.9 cm and 0.050- 0.066 cm. The model prediction was satisfactory, with moisture significantly influencing maize organ morphogenesis. Due to the substandard test conditions, the model moisture factor was not established. The next stage of the model should focus on the coupling of the morphogenesis of water and nitrogen in maize organs. The model should also be tested for much more variety and wider geographical scope.