Detailed temporal and physiological dissection of limitations to water and nitrogen uptake efficiency

小麦是最重要的粮食作物之一，粮食高产对全球粮食安全至关重要。在过去的一个世纪里，育种不断提高产量，然而，与气候变化相关的挑战和对作物投入的监管限制越来越抑制了产量潜力。更好地了解源-库活动背后的生理和代谢过程之间的遗传和生理相互作用，对于优化限制产量潜力的适应性反应和解释基因*环境*管理(G*E*M)交互作用至关重要。在之前的一次合作中，一大批优秀的欧洲冬小麦品种在G*E*M背景下进行了广泛的表型鉴定。该项目的结果表明，几十年的选择导致染色体片段的积累，对与源和库有关的产量关键构成性状产生有利影响，如水分和养分利用效率、生物量、辐射拦截效率和绿色树冠持续时间。然而，这些假定的生理优势并不总是导致粮食产量的增加。这表明，作为产量构成性状的源和库性状的有效重组在广泛的环境和管理情景中具有提高遗传增益的巨大潜力。子项目2的目的是分析水分和氮素吸收之间的相互作用，以及它们在生长季节的时间分布。为此，使用两个互补的表型平台(DroughtSpotter XXL和Plantarray)以超高分辨率记录吸水率。这使得不仅可以跟踪整个生长季节的蒸腾模式，而且可以跟踪每一天的蒸腾模式，并将它们与其他表型特征联系起来。同时，将进行水和氮供应对比的多点田间实验，并将使用多光谱反射测量来记录高分辨率的生长动力学。联合数据分析应导致确定小麦性状特征，以便在各自的压力情景下最小限度地权衡冲突。与其他次级项目合作，确定理想类型和确定遗传决定因素是项目的最终目标。

Wheat is one of the most important staple food crops and high grain yields are essential for global food security. Breeding raised yields continuously over the past century, however yield potential is increasingly suppressed by challenges associated with climate change and regulatory restrictions on crop inputs. A better understanding of the genetic and physiological interplay between physiological and metabolic processes underlying source-sink activities is vital to optimise adaptive responses that limit yield potential and to account for genotype*environment*management (G*E*M) interactions. In a previous collaboration, a large panel of elite European winter wheat cultivars was extensively phenotyped in a G*E*M context. Findings from this project suggest that selection over decades resulted in an accumulation of chromosome segments with favourable effects on source- and sink-related key component traits of yield, such as water and nutrient use efficiency, biomass, radiation interception efficiency and green canopy duration. However, these putative physiological advantages did not always result in increased grain yield. This suggests that an efficient recombination of source and sink traits as component traits of yield has great potential to enhance genetic gain in a wide range of environmental and management scenarios.The aim of the subproject 2 is to analyze the interactions between water and nitrogen uptake on the one hand and their temporal distribution along the growing season on the other. For this purpose, the water uptake is recorded in ultra-high resolution by using two complementary phenotyping platforms (DroughtSpotter XXL and Plantarray). This allows to track transpiration patterns not only over the whole growing season, but also within every single day and to relate them to other phenoytypical traits. In parallel, multi-site field experiments with contrasting water and nitrogen supply will be conducted and multispectral reflectance measurements will be used to record growth dynamics at high resolution. The joint data analysis should lead to the determination of wheat trait profiles that allow the smallest trade off conflicts under the respective stress scenarios. In cooperation with the other subprojects, the identification of ideotypes and the determination of genetic determinants represent the final project goal.