Source-sink balance in wheat under abiotic stress: Dissecting the spatio-temporal dynamics of grain filling

非生物胁迫下小麦的源库平衡：剖析籽粒灌浆的时空动态

• 批准号: 518783157
• 负责人: Professor Dr. Rod Snowdon
• 金额: --
• 依托单位: Lehrstuhl für Pflanzenzüchtung
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/518783157?language=en
• 关键词: Source; sink; balance; wheat; under

Wheat is one of the most important staple food crops and high grain yields are essential for global food security. In extensive previous work we confirmed that limitations to wheat yield potential are primarily determined by traits implicated in source-sink relations: Modern cultivars show increases in biomass, nutrient use efficiency, harvest index, light interception and radiation utilisation efficiency along with an elevated grain number. However, all still carry many detrimental alleles for source-sink traits.We performed extensive phenotyping of source- and sink-related traits under diverse environmental and management scenarios in a large panel of historical winter wheat cultivars. This enabled us to identify modern cultivars with enhanced source strength, facilitated by high water and nitrogen uptake efficiency, high biomass potential and/or high radiation interception/use efficiency, or with remarkable sink strength imparted mainly by a high number of grains per unit area. However, these putative physiological advantages did not always result in increased grain yield: Instead, such genotypes often showed sink deficits in terms of irregular grain formation, spatio-temporal variability for grain development, or other source-sink tradeoffs.The aim of this subproject in the Package Proposal “Wheat source-sink relationships and limitations (WheatSouSi)” is to generate detailed data describing the spatial distribution of grain number and grain size in relation to rachis row number on main stems and secondary tillers of genetically diverse winter wheat cultivars, grown under different environmental constraints, and compare this information with other comprehensive source-sink datasets collected in other subprojects. We will also analyze the relationships between stem soluble carbohydrates, pollen viability, grain set and grain weight, in a spatial context along the length of the spike, under different environmental constraints. This data will be used to evaluate benefits and trade-offs of different allelic combinations of key genes involved in fertility and fecundity in relation to the availability of stem soluble carbohydrates under optimal vs. stress conditions. Finally, we will perform joint analyses with cooperating subprojects to investigate abiotic stress responses at different developmental timeponts, to implement stem carbohydrate data into source-sink models, and to evaluate allelic shifts related to traits under co-selection with grain yield as a consequence of breeding. Collectively, these comprehensive joint analyses will give novel insight into the impact of genetic gain for grain yield on source-sink relationships in modern wheat.

小麦是最重要的主粮作物之一，粮食高产对于全球粮食安全至关重要。在之前的大量工作中，我们证实，小麦产量潜力的限制主要是由源库关系所涉及的性状决定的：现代品种显示出小麦产量的增加。生物量、养分利用效率、收获指数、光拦截和辐射利用效率以及增加的籽粒数量然而，所有这些仍然携带许多源库性状的不良等位基因。我们对源和库相关性状进行了广泛的表型分析。在大量历史冬小麦品种的不同环境和管理情景下，这使我们能够识别出具有增强的来源强度的现代品种，这些品种得益于高水和氮吸收效率、高生物量潜力和/或高辐射拦截/利用效率，然而，这些假定的生理优势并不总是导致谷物产量增加：相反，这些基因型经常在不规则的谷物形成、时空方面表现出库赤字。变异性用于粮食开发或其他源库权衡。一揽子提案“小麦源库关系和限制（WheatSouSi）”中该子项目的目的是生成描述与我们还将分析在不同环境限制下生长的遗传多样性小麦冬季品种的主茎和次生分蘖的轴行数，并将这些信息与其他子项目中收集的其他综合源库数据集进行比较。在不同环境限制下，在沿穗长度的空间背景下，茎可溶性碳水化合物、花粉活力、籽粒结实和籽粒重量将用于评估参与关键基因的不同等位基因组合的益处和权衡。最后，我们将与合作子项目进行联合分析，以研究不同发育时间点的非生物胁迫反应，将茎碳水化合物数据应用到其中。源-库模型，并评估与育种导致的与谷物产量共同选择下的性状相关的等位基因转变，这些综合联合分析将为谷物产量遗传增益对源-库关系的影响提供新的见解。在现代小麦中。