Vaccinium darrowii Camp (2n = 2x = 24) is a native North American blueberry species and an important source of traits such as low chill requirement in commercial southern highbush blueberry breeding (Vaccinium corymbosum, 2n = 4x = 48). We present a chromosomal-scale genome of V. darrowii generated by the combination of PacBio sequencing and high throughput chromatin conformation capture (Hi–C) scaffolding technologies, yielding a total length of 1.06 Gigabases (Gb). Over 97.8% of the genome sequences are scaffolded into 24 chromosomes representing the two haplotypes. The primary haplotype assembly of V. darrowii contains 34,809 protein-coding genes. Comparison to a V. corymbosum haplotype assembly reveals high collinearity between the two genomes with small intrachromosomal rearrangements in eight chromosome pairs. With small RNA sequencing, the annotation was further expanded to include more than 200,000 small RNA loci and 638 microRNAs expressed in berry tissues. Transcriptome analysis across fruit development stages indicates that genes involved in photosynthesis are downregulated, while genes involved in flavonoid and anthocyanin biosynthesis are significantly increased at the late stage of berry ripening. A high-quality reference genome and accompanying annotation of V. darrowii is a significant new resource for assessing the evergreen blueberry contribution to the breeding of southern highbush blueberries.

中文翻译：

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高质量的参考基因组和注释有助于了解常绿蓝莓 (Vaccinium darrowii) 的浆果发育

越橘营地（2n= 2X= 24) 是北美本土的蓝莓品种，是商业性南方高丛蓝莓育种中低温要求低等性状的重要来源 (越橘, 2n= 4X= 48)。我们提出了一个染色体规模的基因组V. darrowii由 PacBio 测序和高通量染色质构象捕获 (Hi-C) 支架技术相结合生成，总长度为 1.06 Gigabases (Gb)。超过 97.8% 的基因组序列被搭建成代表两种单倍型的 24 条染色体。的初级单倍型组装V. darrowii包含 34,809 个蛋白质编码基因。比较五、伞形花序单倍型组装揭示了两个基因组之间的高度共线性，在八对染色体中具有小的染色体内重排。通过小 RNA 测序，注释进一步扩展至包括超过 200,000 个小 RNA 基因座和 638 个在浆果组织中表达的 microRNA。跨果实发育阶段的转录组分析表明，参与光合作用的基因被下调，而参与黄酮类和花青素生物合成的基因在浆果成熟后期显着增加。高质量的参考基因组和随附的注释V. darrowii是评估常绿蓝莓对南方高丛蓝莓育种贡献的重要新资源。