Integration of genome-wide association study, linkage analysis, and population transcriptome analysis to reveal the TaFMO1-5B modulating seminal root growth in bread wheat.

Main Content:
Bread wheat, one of the keystone crops for global food security, is challenged by climate change andresource shortage. The root system plays a vital role in water and nutrient absorption, making it essentialfor meeting the growing global demand. Here, using an association-mapping population composed of 406accessions, we identifiedQTrl.Rs-5Bmodulating seminal root development with a genome-wide associationstudy and validated its genetic effects with two F5segregation populations. Transcriptome-wide associationstudy prioritizedTaFMO1-5B, a gene encoding the flavin-containing monooxygenases, as the causal geneforQTrl.Rs-5B, whose expression levels correlate negatively with the phenotyping variations among ourpopulation.
The lines silenced forTaFMO1-5Bconsistently showed significantly larger seminal roots in dif-ferent genetic backgrounds. Additionally, the agriculture traits measured in multiple environments showedthatQTrl.Rs-5Balso affects yield component traits and plant architecture-related traits, and its favorablehaplotype modulates these traits toward that of modern cultivars, suggesting the application potential ofQTrl.Rs-5Bfor wheat breeding. Consistently, the frequency of the favorable haplotype ofQTrl.Rs-5Bincreased with habitat expansion and breeding improvement of bread wheat. In conclusion, our findingsidentified and demonstrated the effects ofQTrl.Rs-5Bon seminal root development and illustrated that it isa valuable genetic locus for wheat root improvement.