A chromosome-level genome sequence of Chrysanthemum seticuspe, a model species for hexaploid cultivated chrysanthemum.
Michiharu Nakano, Hideki Hirakawa, Eigo Fukai, Atsushi Toyoda, Rei Kajitani, Yohei Minakuchi, Takehiko Itoh, Yohei Higuchi, Toshiaki Kozuka, Hidemasa Bono, Kenta Shirasawa, Ippei Shiraiwa, Katsuhiko Sumitomo, Tamotsu Hisamatsu, Michio Shibata, Sachiko Isobe, Kenji Taniguchi & Makoto Kusaba*
Chrysanthemums are one of the most industrially important cut flowers worldwide. However, their segmental allopolyploidy and self-incompatibility have prevented the application of genetic analysis and modern breeding strategies. We thus developed a model strain, Gojo-0 (Chrysanthemum seticuspe), which is a diploid and self-compatible pure line. Here, we present the 3.05 Gb chromosome-level reference genome sequence, which covered 97% of the C. seticuspe genome. The genome contained more than 80% interspersed repeats, of which retrotransposons accounted for 72%. We identified recent segmental duplication and retrotransposon expansion in C. seticuspe, contributing to arelatively large genome size. Furthermore, we identified a retrotransposon family, SbdRT, which was enriched in gene-dense genome regions and had experienced a very recent transposition burst. We also demonstrated that the chromosome-level genome sequence facilitates positional cloning in C. seticuspe. The genome sequence obtained here can greatly contribute as a reference for chrysanthemum in front-line breeding including genome editing.
- : Communications Biology
- : 10.1038/s42003-021-02704-y
- : https://www.nature.com/articles/s42003-021-02704-y