Musa ornata and M. velutina are members of the Musaceae family and are indigenous to the South and Southeast Asia. They are very popular in the horticultural market, but the lack of genomic sequencing data and genetic studies has hampered efforts to improve their ornamental value. In this study, we generated the first chromosome-level genome assemblies for both species by utilizing Oxford Nanopore long reads and Hi-C reads. The genomes of M. ornata and M. velutina were assembled into 11 pseudochromosomes with genome sizes of 427.85 Mb and 478.10 Mb, respectively. Repetitive sequences comprised 46.70% and 50.91% of the total genomes for M. ornata and M. velutina, respectively. Differentially expressed gene (DEG) and Gene Ontology (GO) enrichment analyses indicated that upregulated genes in the mature pericarps of M. velutina were mainly associated with the saccharide metabolic processes, particularly at the cell wall and extracellular region. Furthermore, we identified polygalacturonase (PG) genes that exhibited higher expression level in mature pericarps of M. velutina compared to other tissues, potentially being accountable for pericarp dehiscence. This study also identified genes associated with anthocyanin biosynthesis pathway. Taken together, the chromosomal-level genome assemblies of M. ornata and M. velutina provide valuable insights into the mechanism of pericarp dehiscence and anthocyanin biosynthesis in banana, which will significantly contribute to future genetic and molecular breeding efforts.

中文翻译：

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Musa ornata 和 M. velutina 的染色体水平基因组组装提供了对香蕉果皮开裂和花青素生物合成的见解

花蕉 (Musa ornata) 和绒毛蕉 (M. velutina) 属于芭蕉科 (Musaceae)，原产于南亚和东南亚。它们在园艺市场上非常受欢迎，但缺乏基因组测序数据和遗传学研究阻碍了提高其观赏价值的努力。在这项研究中，我们利用 Oxford Nanopore 长读长和 Hi-C 读长为这两个物种生成了第一个染色体水平的基因组组装。M. ornata 和 M. velutina 的基因组被组装成 11 条假染色体，基因组大小分别为 427.85 Mb 和 478.10 Mb。重复序列分别占 M. ornata 和 M. velutina 总基因组的 46.70% 和 50.91%。差异表达基因（DEG）和基因本体（GO）富集分析表明，毛绒绒成熟果皮中上调的基因主要与糖代谢过程有关，特别是在细胞壁和细胞外区域。此外，我们还发现，与其他组织相比，多聚半乳糖醛酸酶（PG）基因在毛绒绒毛绒成熟果皮中表现出更高的表达水平，这可能是导致果皮开裂的原因。这项研究还鉴定了与花青素生物合成途径相关的基因。总而言之，M. ornata 和 M. velutina 的染色体水平基因组组装为香蕉果皮开裂和花青素生物合成的机制提供了有价值的见解，这将对未来的遗传和分子育种工作做出重大贡献。