目的 解析远志Polygala tenuifolia叶绿体基因组信息序列特征和确定其在远志属的系统位置。方法 获得远志叶绿体基因组序列，借助GeSeq、Chloroplot、MISA、REPute、Tandem repeats finder、CodonW、Geneious、IRscope、MAFFT 7和IQtree2.0.5等生物信息学工具进行序列分析、密码子偏好分析、远志属基因组比较分析和系统发育研究。结果 远志的叶绿体基因组全长165 423 bp，为典型的环状四段式结构；包括1个大单拷贝区（large single copy，LSC；83 699 bp），1个小单拷贝区（small single copy，SSC；8044 bp）和1对反向重复区（inverted repeats，IRs；36 840 bp），该基因组共注释到135个基因，包括8个rRNA基因、38个tRNA基因和89个蛋白编码基因。该基因组中共检测到161个SSR位点，223条散在重复序列，90条串联重复序列；亮氨酸（Leu）是远志叶绿体基因组中使用次数最高的氨基酸（10.21%），同义密码子相对使用频次（RSCU）＞1的密码子有35种且均以A/U结尾；序列长度、基因组成以及GC含量等方面相对保守。IR边界分析除了西南远志Polygala crotalarioides和密花远志Polygala karensium外，其余远志属边界高度保守；基于远志科9个物种的叶绿体基因组数据同时选择远志属的近缘类鸦胆子Brucea javanica和九里香Murraya exotica作为外类群，采用最大似然法和邻接法分别构建系统发育树，支持率均为100，显示远志P.tenuifolia与卵叶远志Polygala sibirica、瓜子金Polygala japonica和香港远志Polygala hongkongensis聚类到一起，能够反映远志属的亲缘关系。结论 远志与卵叶远志、瓜子金和香港远志的亲缘关系最近。首次采用生物信息学分析方法对远志叶绿体基因组进行了全面、深度解析，结果将为远志属药用植物的遗传多样性分析以及新品系的遗传育种研究等提供理论依据。

Objective To analyze the chloroplast genome information of Polygala tenuifolia and determine its phylogenetic position in Polygala genus. Methods The chloroplast genome sequence of P. tenuifolia was obtained. Bioinformatics tools of GeSeq, Chloroplot, MISA, REPute, Tandem repeats finder, CodonW, Geneious, IRscope, MAFFT 7 and IQtree2.0.5 were used for sequence analysis, codon preference analysis, genome comparative analysis and phylogenetic study of Polygala. Results The chloroplast genome of P. tenuifolia was 165 423 bp in length, which was a typical circular four-segment structure, including a large single copy region (LSC; 83 699 bp), a small single copy region (SSC; 8044 bp) and a pair of reverse repeat region (IRs; 36 840 bp). The total of 135 genes were annotated, including eight rRNA genes, 38 tRNA genes and 89 protein coding genes. The total of 161 SSR location, 223 scattered repeats and 90 tandem repeats were detected in the genome. Leucine (Leu) was the most frequently used amino acid (10.21%) in the chloroplast genome of P. tenuifolia, and there were 35 codons with relative synonymous codon usage (RSCU)＞1, all of which ended in A/U, the chloroplast genome of was relatively conservative in terms of sequence length, gene composition and GC content. Except P. crotalarioides and P. karensium, the boundaries of other genera were highly conservative by IR boundary analysis. Based on the chloroplast genome data of nine species in the family Polydiaceae, we selected the related member of the genus Polygala: Brucea javanica and Murraya exotica as the outgroup. The phylogenetic trees were constructed by maximum likelihood and neighbor-joining method, with support rates of 100. The results showed that P. tenuifolia was clustered with P. sibirica, P. japonica and P. hongkongensis, which could reflect the genetic relationship of Polygala. Conclusion P. tenuifolia had the closest relationship with P. sibirica, P. japonica, P. hongkongensis. In this study, the chloroplast genome of P. tenuifolia was analyzed comprehensively and deeply for the first time by using bioinformatics analysis method, which will provide theoretical basis for genetic diversity analysis of medicinal plants and genetic breeding research of new strains of Polygala.

R286.12

山西省科技厅应用基础研究项目（201901D111039）；山西省科技成果转化引导专项（202104021301064）；吕梁市引进高层次科技人才重点研发项目（2021RC-2-13）；山西省基础研究计划（20210302123312）