玉米地上主要器官形态建成的动态模拟

构建玉米茎秆、叶片和穗等器官的形态建成模型,可为玉米器官建成的定量预测和虚拟玉米生长系统的建立提供理论参考。以‘金山27’、‘先玉335’、‘伟科702’和‘郑单958’等玉米品种为试验材料,构建玉米器官形态建成的动态模拟模型。模型以生理发育时间(PDT)为时间步长,以生理发育日来衡量茎秆、叶片和穗的生长进程与生长次序,以品种遗传参数为基础确定其他模型参数,引入了最小含氮量、最大含氮量和临界含氮量订正氮素的影响。不同品种、不同试验点的检验结果表明,节间长度的模拟误差为0~2.5 cm,RMSE为0.2~0.8 cm;节间粗度的模拟误差为0.001~0.397 cm,RMSE为0.050~0.156 cm;叶片长度的模拟误差为0~2.6 cm,RMSE为0.5~1.1 cm;叶片宽度的模拟误差为0~1.5 cm,RMSE为0.1~0.5 cm;雌穗长度的模拟误差为0.1~1.4 cm,RMSE为0.4~0.7 cm;雌穗粗度的模拟误差为0~0.255 cm,RMSE为0.070~0.141 cm;雄穗长度的模拟误差为0.1~2.1 cm,RMSE为0.5~0.9 cm;雄穗粗度的模拟误差为0.001~0.158 cm,RMSE为0.050~0.066 cm。模型表现出较好的预测性和可靠性。

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.