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Exploring the molecular mechanism underlying plant architecture and breeding new varieties suitable for mechanized harvesting are primary objectives for rapeseed breeders in China. However, few genes controlling plant architecture have been cloned in . In this study, SX3, a scattered-bud line with a dwarf and compact plant architecture, was characterized. To identify the genes underlying bud arrangement, plant height and branch angle, segregating populations were constructed by crossing SX3 with two clustered-bud lines with a tall and loose plant architecture. Genetic analysis revealed that the scattered-bud trait (SBT) was controlled by a single dominant gene, . is likely a pleiotropic gene that simultaneously controls plant height and branch angle. Using BSA-seq analysis, was mapped to a 4.15 Mb region on ChrA10. Owing to the lack of recombinants within this region, it was infeasible to finely map . RNA-seq analysis of BC plants with contrasting inflorescence and plant architectures revealed that the upregulation of genes involved in amino acid and lipid metabolism and genes encoding MADS-box transcription factors is related to the the phenotype of SX3. These findings together with comparative sequencing indicated that , , and are candidate genes for . Markers closely linked to the scattered-bud trait were developed for selecting dwarf and compact plants. These findings provide molecular markers and germplasms for breeding new varieties with ideal plant types and lay a theoretical foundation for cloning key genes and elucidating the genetic basis of inflorescence and plant architectures in

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s11032-025-01556-2.