Zhong Qianqian, Wang Zehuan, Xu Jiaju, Yan Li, Sun Qingwen
Department of Traditional Chinese Medicine Resources and Development, College of Pharmacy, Guizhou University of Traditional Chinese Medicine, Guiyang, 550025, Guizhou, China.
Sci Rep. 2025 Mar 27;15(1):10566. doi: 10.1038/s41598-025-95325-y.
Melanoseris, a diverse genus in the Lactucinae subtribe, has 21 species in China, with 13 being endemic. The high diversity of this genus presents taxonomic challenges, particularly in the M. cyanea group, where overlapping distributions and transitional morphological traits complicate classification. This study aims to analyze the chloroplast genomes of Melanoseris, with a focus on the M. cyanea group, to explore structural differences and phylogenetic relationships among these closely related species. We analyzed the chloroplast genomes of 16 Melanoseris samples, including 12 new genomes from the M. cyanea group. The genome sizes ranged from 152,255 to 152,558 bp and exhibited a typical quadripartite structure, with an average GC content of 37.7%. Each genome encodes 132 genes, including 87 protein-coding genes, 37 tRNAs, and 8 rRNAs. Repeat analysis identified 89 to 105 dispersed repeats, 24 to 28 tandem repeats, and 35 to 39 SSRs, with mononucleotide A/T repeats being the most common. Sequence alignment revealed that variable regions were mainly concentrated in the single-copy regions. Nucleotide diversity ranged from 0 to 0.00485, highlighting 10 mutation hotspot regions. Phylogenetic analysis showed a limited differentiation among species within the M. cyanea group. This research enhances our understanding of the genetic diversity of Melanoseris, laying the foundation for future taxonomic and phylogenetic studies.
黑背苣属是莴苣亚族中一个多样化的属，在中国有21个物种，其中13个为特有种。该属的高度多样性带来了分类学挑战，特别是在蓝背黑背苣组中，分布重叠和形态特征过渡使分类变得复杂。本研究旨在分析黑背苣属的叶绿体基因组，重点关注蓝背黑背苣组，以探索这些近缘物种之间的结构差异和系统发育关系。我们分析了16个黑背苣属样本的叶绿体基因组，包括来自蓝背黑背苣组的12个新基因组。基因组大小在152,255至152,558 bp之间，呈现典型的四分体结构，平均GC含量为37.7%。每个基因组编码132个基因，包括87个蛋白质编码基因、37个tRNA和8个rRNA。重复序列分析鉴定出89至105个分散重复序列、24至28个串联重复序列和35至39个简单序列重复（SSR），其中单核苷酸A/T重复最为常见。序列比对显示可变区主要集中在单拷贝区域。核苷酸多样性在0至0.00485之间，突出了10个突变热点区域。系统发育分析表明蓝背黑背苣组内物种间的分化有限。本研究增进了我们对黑背苣属遗传多样性的理解，为未来的分类学和系统发育研究奠定了基础。
