水分对切花百合叶面积影响的预测模型研究

Simulation model for predicting the effects of substrate water potential on leaf area of cut lily

叶面积既是重要的花卉作物外观品质指标,又是作物生长和蒸腾模型中所必需的作物参数。为建立水分对叶面积影响的预测模型,该研究以切花百合品种'索邦'(Lilium'Sorbonne')为试验材料,于2009年3月至2010年1月在南京市农科所温室内进行了不同定植期和不同水分处理的栽培试验。首先根据试验数据,确定了切花百合正常生长的临界基质水势。然后定量分析了不同定植期和不同水分处理切花百合叶面积的变化规律,以及基质水势对百合最大叶长、最大叶长伸长速率和到达最大叶长累积的光温指数动态的影响。在此基础上,进一步建立基质水势对切花百合叶面积指数影响的动态预测模型,并采用与建模数据相独立的试验数据对模型进行了检验。结果表明,模型对百合展叶数、单叶叶长和叶面积指数预测效果较好,预测值与实测值之间基于1∶1线的决定系数(r2)分别为0.96、0.82、0.97,相对回归估计标准误差(rRMSE)分别为6.32%、8.78%、7.12%。该模型能较好地预测水分对切花百合叶面积的动态影响,可为进一步优化切花百合生产的水分管理提供决策支持。

Leaf area is not only an important external quality trait of flower plants,but also a parameter used in the photosynthesis-driven crop growth model.The aim of this study was to develop a model for predicting the effects of water supply on plant leaf area.For this purpose,experiments of cut lily （Lilium cv ＇Sorbonne＇） with different planting dates and different levels of water treatment were conducted in a multi-span greenhouse located at Nanjing from March 2009 to January 2010.Based on the experimental data,the critical water potential for cut lily growth was then determined.The seasonal changes of leaf area of the cut lily plants,and the impacts of substrate water potential on the maximum leaf length （Lmax）,the increasing rate of Lmax with leaf rank before the maximum length of matured leaf appeared,the photo-thermal index accumulated from the date when the leaf appears to the date when the leaf reaches its maximal length were quantitatively investigated.Based on these quantitative analyses,a dynamic model was developed for predicting the effects of substrate water potential on leaf area index of cut lily plants.Independent experimental data were used to validate the model.The results showed that the model gave good predictions of leaf area index.The coefficient of determination （r2） between the simulated and the measured values of number of leaf unfolding,individual leaf length and leaf area index were 0.96,0.82,0.97,respectively.The relative root mean square error （rRMSE） between the simulated and the measured values were 6.32%,8.78%,7.12% respectively,for number of leaf unfolding,individual leaf length and leaf area index.The model developed in this study can satisfactorily predict the dynamics of the leaf area of cut lily organs,hence,can be used for optimizing water management for cut lily production.