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

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.