Achieving yield stability by meta-mechanisms determining the stable canopy development in winter wheat

冬小麦的产量稳定性是德国农民选择冬小麦品种的重要指标。我们对导致产量稳定的生理机制的了解非常有限，因为评估一种基因型的产量稳定性需要多年、地点、农业实践和与其他基因型进行比较的田间试验，这是一个耗时和劳动密集型的过程。在这里，我们建议使用概率方法结合表型组学和大规模建模来重新审视产量稳定性，这允许利用与产量变异性相关的“元机制”。我们进一步假设，在营养阶段能够实现稳定冠层发育的品种由于籽粒灌浆时营养器官中氮和水溶性碳的储存而更加稳定。以产量水平相近但产量稳定性差异较大的6个小麦品种为研究对象，建立了一个以物候、冠层发育、结构和光合作用控制元机制为核心的机制-功能-结构植物模型，并进行了参数化和评价。该模型将用于创建虚拟基因型，并在大量环境情景下模拟其冠层发育和产量。模型结果将用于确定哪些生理机制组合导致稳定产量。

Yield stability of winter wheat is a highly relevant trait for cultivar choice by German farmers. Our knowledge about the physiological mechanisms leading to yield stability is very limited because assessing the yield stability of a genotype requires field experiments across multiple years, locations, agriculture practices and comparisons with other genotypes, a time consuming and labour intensive procedure. Here we propose to revisit yield stability using the probabilistic approach in combination with phenomics and large-scale modelling, which allows exploiting the “meta-mechanisms” related to the variability in yield. We further hypothesize that cultivars able to achieve stable canopy development during the vegetative phase are more stable due to the storages of nitrogen and water soluble carbon in the vegetative organs for grain filling. Using six wheat cultivars with similar yield level but contrasting yield stability, a mechanistic functional-structural plant model focusing on the meta-mechanisms controlling the phenology, canopy development, architecture and photosynthesis will be parameterized and evaluated. This model will be used to create virtual genotypes and their canopy development and yield will be simulated with large number of environmental scenarios. The model outcomes will be used to identify which combinations of physiological mechanisms resulting stable yield.