The functions of phenotypic plasticity in plant-plant interactions and canopy productivity

在所有的农业系统和育种者的田间，生长中的植物通过调节其形态和生理特征，不断地与邻近植物所创造的小气候相互作用。这些调节的能力，即表型可塑性，对林冠内单株的资源获取和适应性至关重要。然而，表型可塑性有利于植物间资源捕获的竞争，而不利于冠层总生产力。直到今天，定量剖析这些植物-植物相互作用对植物和冠层性能的影响的实验方法仍然非常缺乏。我们建议利用表型组学和3d建模方法的最新进展来了解植物-植物相互作用的表型可塑性策略及其对冠层生产力的功能影响。利用228个冬小麦基因型，对叶片、茎和根性状的塑性驯化对资源捕获、异质冠层中单个基因型的适合度和冠层总生产力的影响进行了7个主要假设的检验。全基因组关联研究将用于确定负责一个性状对环境波动的可塑性或不变反应的基因组区域。利用机械功能-结构植物模型（FSPM）整合叶片、茎和根对冠层小气候的动态适应，进行大规模的虚拟实验，从而确定在各种环境情景下最小化植物间竞争和最大化冠层生产力的理想策略。此外，我们提出了一个理论框架（TF），通过校正基因型在异质冠层下的表现及其竞争力来预测在同质冠层中生长的基因型的表现。所提出的FSPM和TF有望分别为农业系统的设计（例如品种混合）和育种者领域中由于植物-植物竞争而产生的选择偏差提供见解。

In all agriculture systems and breeders’ fields, growing plants interact continuously with the microclimate created by their neighboring plants by adjusting their morphological and physiological characteristics. The ability of these adjustments, namely phenotypic plasticity, is essential for resource capture and fitness of individual plant in the canopy. However, phenotypic plasticity can favor competition of resource capture between plants and penalize total canopy productivity. Experimental methods which quantitatively dissect the effects of these plant-plant interactions on plant and canopy performance into physiologically interpretable parameters are astonishingly scarce until today. We propose to use recent advances in phenomics and 3D-dmodelling approach to understand the strategies of phenotypic plasticity for plant-plant interactions and their functional effects on canopy productivity. We plan to use 228 winter wheat genotypes to test seven main hypotheses related to the effects of plastic acclimations of leaf, stem and root traits on the resource capture, fitness of individual genotype in a heterogeneous canopy and the total canopy productivity. Genome-wide association study will be used to identify the genomic regions responsible for the plastic or invariant response of a trait to the environmental fluctuations. A mechanistic functional-structural plant model (FSPM) will be used to integrate the dynamic acclimation of leaf, stem and root to the microclimate in a canopy will be constructed to conduct large-scale virtual experiments, which allow identification of the ideal strategies for minimizing plant-plant competition and maximizing canopy productivity under various environmental scenarios. Furthermore, we propose a theoretical framework (TF) to predict the performance of a genotype grown in a homogenous canopy by correcting the performance of this genotype under heterogeneous canopy with its competitiveness. The proposed FSPM and TF are expected to provide insights into the design of agricultural systems (e.g. varietal mixture) and the selection bias due to plant-plant competition in the breeders´ fields, respectively.