Stage-specific response variability of yield components to environmental fluctuations during generative development of winter wheat

• Applicant: Professor Dr. Tsu-Wei Chen
• Subject Area: Plant Cultivation, Plant Nutrition, Agricultural Technology
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 545869818

Yield components of winter wheat include spike number, kernel number per spike, and thousand kernel weight. Their formation determines grain yield, but they vary considerably under field conditions due to significant positive or detrimental effects of environmental fluctuations on them during their development. Therefore, it is important to understand the cultivar- and stage-specific impacts of short-term natural fluctuations in environmental variables on the formation of yield components. In this project, two datasets from large-scale field experiments will be analyzed using a novel statistical approach to identify the cultivar- and stage-specific linear or non-linear responses of yield components to environmental variables. Subsequently, sensitive and insensitive cultivars will be selected for validation through two series of greenhouse and growth chamber experiments. Based on our preliminary studies, the validation experiments will focus on two particularly novel observations. Firstly, global radiation positively influences thousand kernel weight shortly before seed desiccation, a period coinciding with maximum grain expansion and flag leaf senescence. We hypothesize that this positive effect is not achieved through increased canopy photosynthesis but through enhanced remobilization of water-soluble carbohydrates. Secondly, an increase in night temperature positively affects thousand kernel weight between the white and green anther stages by increasing cell size. Furthermore, genome-wide association studies will be employed to identify genomic regions associated with stage-specific sensitivities. The knowledge gained will provide insights into eco-physiological and genetic aspects of yield formation and contribute valuable information for breeding yield stability.

• DFG Programme: Research Grants