Dissecting Wheat Grain Yield Drivers in a Mapping Population in the UK

Improving crop yields arises as a solution to ensure food security in the future scenarios of a growing world population, changes in food consumption patterns, climate change, and limitations on resources allocated to agriculture. Defining traits that can be reliable cornerstones to yield improvement and understanding of their interaction and influence on yield formation is an important part of ensuring the success of breeding programs for high yields. Traits that can drive yield increases, such as light interception and conversion efficiency, as well as carbon assimilation and allocation, were intensively phenotyped in a double-haploid wheat mapping population grown under field conditions in the UK. Traits were analysed for their correlation to yield, genetic variation, and broad-sense heritability. Canopy cover and reflectance, biomass production, and allocation to stems and leaves, as well as flag leaf photosynthesis at a range of light levels measured pre- and post-anthesis correlated with plant productivity and contributed to explaining different strategies of wheat lines to attain high grain yields. This research mapped multiple traits related to light conversion into biomass. The findings highlight the need to phenotype traits throughout the growing season and support the approach of targeting photosynthesis and its components as traits for breeding high yielding wheat.