The genome of the mesopolyploid crop species Brassica rapa was sequenced and annotated, revealing insights into its genetic structure and evolution. Brassica rapa, one of the two ancestral species of oilseed rape, has undergone a genome triplication, making it a mesohexaploid. The genome sequence covers 283.8 Mb, with 98% coverage of the gene space, and includes 41,174 protein-coding genes. The genome shows significant variation in gene loss among triplicated segments, with one segment retaining 70% of ancestral genes compared to 46% and 36% in the other two. The genome contains a high proportion of transposable elements, which may contribute to its morphological diversity. The genome sequence provides a valuable resource for comparative and evolutionary analysis of Brassicaceae genomes and for genetic improvement of Brassica crops. The genome also reveals that Brassica species have a high propensity for morphological variation, which is linked to their rapid evolutionary rate and gene family expansions. The genome sequence highlights the importance of polyploidy in plant evolution, with Brassica species showing unique characteristics in gene retention and expression. The study also identifies key gene families involved in plant development and environmental adaptation, such as auxin-related genes and TCP genes. The genome sequence provides a foundation for further research into the genetic mechanisms underlying plant morphological evolution and domestication. The study was conducted by a consortium of researchers from various institutions, and the findings have implications for understanding genome evolution and crop improvement.The genome of the mesopolyploid crop species Brassica rapa was sequenced and annotated, revealing insights into its genetic structure and evolution. Brassica rapa, one of the two ancestral species of oilseed rape, has undergone a genome triplication, making it a mesohexaploid. The genome sequence covers 283.8 Mb, with 98% coverage of the gene space, and includes 41,174 protein-coding genes. The genome shows significant variation in gene loss among triplicated segments, with one segment retaining 70% of ancestral genes compared to 46% and 36% in the other two. The genome contains a high proportion of transposable elements, which may contribute to its morphological diversity. The genome sequence provides a valuable resource for comparative and evolutionary analysis of Brassicaceae genomes and for genetic improvement of Brassica crops. The genome also reveals that Brassica species have a high propensity for morphological variation, which is linked to their rapid evolutionary rate and gene family expansions. The genome sequence highlights the importance of polyploidy in plant evolution, with Brassica species showing unique characteristics in gene retention and expression. The study also identifies key gene families involved in plant development and environmental adaptation, such as auxin-related genes and TCP genes. The genome sequence provides a foundation for further research into the genetic mechanisms underlying plant morphological evolution and domestication. The study was conducted by a consortium of researchers from various institutions, and the findings have implications for understanding genome evolution and crop improvement.