Effects of canopy structure on salinity stress in cucumber (Cucumis sativus L.)

盐度通过渗透和离子效应降低黄瓜（Cucumis sativus L.）产量。对于给定的大气条件，我们假设存在一个最佳的冠层结构，在该结构下，水分利用效率最大，单位干物质生产的盐积累最小。利用功能-结构植物模型（FSPM）对冠层的生理过程进行整合，可以预测冠层结构的优化。该模型需要表征渗透胁迫对植物形态和气孔导度的影响，系统不同隔室中有毒离子的积累及其动态，以及它们在叶片中的毒性作用。实验将进行参数化一个扩展的黄瓜FSPM。在FSPM的硅实验中，我们试图确定哪种冠层结构可以在最小的离子应力下实现最大的长期水利用效率。将通过比较温室中不同的冠层结构来评估计算机实验的结果。最后，FSPM将用于研究气孔导度敏感性降低或叶片膨大等个体耐盐机制的改善在多大程度上有助于整株耐盐。

Salinity reduces the productivity of cucumber (Cucumis sativus L.) through osmotic and ionic effects. For given atmospheric conditions we hypothesize the existence of an optimal canopy structure at which water use efficiency is maximal and salt accumulation per unit of dry matter production is minimal. This canopy structure optimum can be predicted by integrating physiological processes over the canopy using a functional-structural plant model (FSPM). This model needs to represent the influence of osmotic stress on plant morphology and stomatal conductance, the accumulation of toxic ions and their dynamics in the different compartments of the system, and their toxic effects in the leaf. Experiments will be conducted to parameterize an extended cucumber FSPM. In in-silico experiments with the FSPM we attempt to identify which canopy structure could lead to maximum long-term water use efficiency with minimum ionic stress. The results from in-silico experiments will be evaluated by comparing different canopy structures in greenhouses. Finally, the FSPM will be used to investigate to which extent the improvement of individual mechanisms of salt tolerance like reduced sensitivity of stomatal conductance or leaf expansion can contribute to whole-plant salt tolerance.