目的 以桔梗Platycodon grandiflorus为材料，分析其叶绿体基因组特征，探究不同地区桔梗叶绿体基因组的差异及桔梗科其他物种的系统发育关系。方法 利用Illumina NovaSeq测序平台对桔梗叶绿体全基因组进行测序，完成其组装、注释和特征分析，采用生物信息学方法对不同地区桔梗进行比较基因组分析和系统发育分析。结果 桔梗叶绿体基因组全长172 770 bp，呈现典型的环状四分体结构，总GC含量为38.10%，注释到139个基因，其中蛋白质编码基因95个，核糖体RNA 8个和转运RNA 36个。经序列分析鉴定出139个SSR位点，大部分重复由A和T组成。该叶绿体基因组密码子偏好性A/U大于G/C。边界分析表明，不同地区桔梗的JLA边界区域存在差异。对比不同地区桔梗叶绿体基因组序列发现21个变异区间，包括ycf1、psbC、rps18和rpoB等编码区以及rpl32-trnL、trnS-psbZ和trnN-ycf1等非编码区。基于最大似然法（maximum likelihood method，ML）对桔梗及其他17种桔梗科植物进行系统发育分析，发现桔梗科物种形成一个单系群，各属物种聚为一束，支持率达100%。结论 桔梗科物种聚为一支与传统相符合，不同地区桔梗叶绿体基因组序列存在显著差异，为后期开展分子鉴定及群体遗传学研究提供提供科学依据。

Objective To explore the differences of chloroplast genomes of Jiegeng[Platycodon grandiflorus (Jacq.) A. DC.] from different regions and phylogenetic relationship between it and its relatives, the complete chloroplast genome of P. grandiflorus was sequenced and assembled. Methods We sequenced the chloroplast genome of P. grandiflorus using Illumina NovaSeq sequencing platform, and assembled, annotated and characterized them, compared the chloroplast genomes sequences using bioinformatics methods, and analyzed the phylogenetic relationships. Results The full chloroplast genome of P. grandiflorus was 172 770 bp in length and its GC content was 38.10%, with a typical circular tetrad structure. A total of 139 genes were annotated, including 95 protein-coding genes, 8 rRNA genes, and 36 tRNA genes. A total of 139 SSRs were detected, most of which consisted of A and T. The codon preference of A/U was greater than that of G/C. The comparison of boundary region showed that there were differences in inverted repeat region (IR) of two different regions of P. grandiflorus. Analyses of sequences from the two different regions of P. grandiflorus showed that 21 diverse regions are found in the protein coding regions such as psbC,rps18, rpoB, ycf1, and in the intergenic regions such as rpl32-trnL, trnS-psbZ, trnN -ycf1. Based on the maximum likelihood method (ML) for phylogenetic analysis of P. grandiflorus and 17 other Campanulaceae plants, it was found that Campanulaceae species formed a single monophyletic group. The clustering of plants of the same genus was in line, and the support rate reached 100%. Conclusion The clustering of Campanulaceae species was in line with tradition. There were significant differences in chloroplast genome sequence of P. grandiflorus among different regions. These results will provide an important basis for the further development of molecular identification and population genetics.

R286.12

基于基因组学的“盂桔梗”道地性研究（SZY-YQZX-2019006）；山西省应用基础研究计划项目（201901D211540）；山西道地药材品质形成机制创新团队（2022TD2009）；山西中医药大学中药资源学（2023XKJS-23）