The liquorice tribe Glycyrrhizeae is a leguminous herbaceous group of plants comprised of the genera Glycyrrhiza and Glycyrrhizopsis. Some Glycyrrhiza taxa contain glycyrrhizin, a pharmacologically significant sweet substance that also has applications in crafting industrial materials. Here, we utilized an expanded taxon sampling of Glycyrrhizeae to reconstruct the phylogenetic relationships in the tribe based on genome skimming data, including whole chloroplast genomes, nuclear ribosomal DNA, and low-copy nuclear DNA. We also launched machine learning analysis (MLA) for one species pair with controversial taxonomic boundary. The integrated results indicated Glycyrrhizopsis should be split from Glycyrrhiza, while the former genus Meristotropis should be treated as part of Glycyrrhiza. Glycyrrhizopsis includes two species, Glycyrrhizopsis asymmetrica and Glycyrrhizopsis flavescens, and we recognize 13 species in Glycyrrhiza: Glycyrrhiza acanthocarpa, Glycyrrhiza astragalina, Glycyrrhiza bucharica, Glycyrrhiza echinata, Glycyrrhiza foetida, Glycyrrhiza glabra, Glycyrrhiza gontscharovii, Glycyrrhiza lepidota, Glycyrrhiza macedonica, Glycyrrhiza pallidiflora, Glycyrrhiza squamulosa, Glycyrrhiza triphylla, and Glycyrrhiza yunnanensis. We propose a broader G. glabra that includes former Glycyrrhiza aspera, G. glabra s.s., Glycyrrhiza inflata, and Glycyrrhiza uralensis, and represents the glycyrrhizin-contained medicinal group. Our ancestral state inferences show the ancestor of Glycyrrhiza lacked glycyrrhizin, and the presence of glycyrrhizin evolved twice within Glycyrrhiza during the last one million years. Our integrative phylogenomics-MLA study not only provides new insights into long-standing taxonomic controversies of Glycyrrhizeae, but also represents a useful approach for future taxonomic studies on other plant taxa.

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基于系统基因组学和机器学习分析的甘草族（豆科：甘草科）物种定界

甘草族甘草科是豆科草本植物群，由甘草属和甘草属组成。一些甘草类群含有甘草甜素，这是一种具有药理学意义的甜味物质，也可用于制作工业材料。在这里，我们利用甘草科的扩展分类单元抽样，根据基因组撇取数据重建该部落的系统发育关系，包括整个叶绿体基因组、核糖体 DNA 和低拷贝核 DNA。我们还针对具有有争议的分类边界的一对物种启动了机器学习分析 (MLA)。综合结果表明甘草应从甘草中分离出来, 而前Meristotropis属应作为Glycyrrhiza的一部分处理。Glycyrrhizopsis includes two species, Glycyrrhizopsis asymmetrica and Glycyrrhizopsis flavescens , and we recognize 13 species in Glycyrrhiza : Glycyrrhiza acanthocarpa , Glycyrrhiza astragalina , Glycyrrhiza bucharica , Glycyrrhiza echinata , Glycyrrhiza foetida , Glycyrrhiza glabra , Glycyrrhiza gontscharovii , Glycyrrhiza lepidota , Glycyrrhiza macedonica ,Glycyrrhiza pallidiflora、Glycyrrhiza squamulosa、Glycyrrhiza triphylla和Glycyrrhiza yunnanensis。我们提出了一个更广泛的G. glabra，包括以前的Glycyrrhiza aspera、G. glabra ss、Glycyrrhiza inflata和Glycyrrhiza uralensis，代表了含有甘草甜素的药用组。我们的祖先状态推论表明，甘草的祖先缺乏甘草甜素，甘草甜素的存在在甘草中进化了两次在过去的一百万年里。我们的综合系统基因组学-MLA 研究不仅为长期存在的甘草科分类学争议提供了新见解，而且代表了未来对其他植物分类群进行分类学研究的有用方法。