目的 研究枣属ZiziphusMill. 16种植物叶绿体基因组特征、结构变异、系统发育、序列多态性和选择压力，为枣属植物的系统发育、分子鉴定及药用植物资源保护等研究提供理论依据。方法 基于已发表的枣属植物叶绿体基因组序列，利用生物信息学方法对其叶绿体基因组进行分析。结果 16个物种叶绿体基因组大小在160 920～162 162 bp，共注释基因数量为122～133个，包括78～85个蛋白编码基因、8个rRNA基因和36～43个tRNA基因。四分区分析发现，一个反向重复区b（inverted repeat b，IRb）/小单拷贝区（small single copy，SSC）边界存在明显差异。串联重复和单核苷酸重复含量最丰富。共线性分析未检测到基因重排，其叶绿体基因组高度保守。基于叶绿体基因组的系统发育分析表明，枣属植物分为6个主要分支。对枣属植物叶绿体基因组进行核苷酸多态性分析，发现高变区主要分布在大单拷贝区（large single copy，LSC）和SSC区域。选择压力分析发现16种枣属植物共有的蛋白质编码基因（coding sequences，CDS）中除了ccsA、ndhA基因受到正选择，其余氨基酸序列高度保守。结论 解析了枣属植物叶绿体基因组结构和特征，探究了枣属植物种间亲缘关系，为枣属物种鉴定、资源保护和开发及系统进化提供理论依据。

Objective The study aims to investigate the chloroplast genome characteristics, structural variations, phylogeny, sequence polymorphism, and selective pressures of 16 species within the genus Ziziphus, providing a theoretical basis for research on the phylogeny, molecular identification, and conservation of medicinal plant resources within the genus. Methods This study analyzed the chloroplast genomes of species within the genus Ziziphus using bioinformatics methods, based on the published chloroplast genome sequences of these species. Results The chloroplast genomes ranged in size from 160 920 to 162 162 bp, with a total of 122 to 133 annotated genes, including 78 to 85 protein-coding genes, 8 rRNA genes, and 36 to 43 tRNA genes. Quadripartite analysis revealed significant differences at the inverted repeat b (IRb)/ small single copy (SSC) boundaries. Tandem and single nucleotide repeats were the most abundant. Collinearity analysis did not detect any gene rearrangements, indicating that the chloroplast genomes are highly conserved. Phylogenetic analysis based on chloroplast genomes showed that Ziziphus plants are divided into six major clades. Nucleotide polymorphism analysis of the chloroplast genomes of Ziziphus plants revealed that highly variable regions are mainly distributed in the large single copy (LSC) and SSC regions. Selection pressure analysis found that among the common protein-coding genes (CDS) of the 16 Ziziphus species, only the ccsA and ndhA genes were under positive selection, while the remaining amino acid sequences were highly conserved. Conclusion This study elucidates the structure and characteristics of chloroplast genomes in the genus Ziziphus and explores the interspecific relationships among Ziziphus plants, providing a theoretical basis for species identification, resource conservation, exploitation, and phylogenetic evolution.

R286.12

国家重点研发计划项目（2019YFD1000102）；山东省科技型中小企业创新能力提升工程项目（2023TSGC0281）；济南市农业科技攻关项目（GG202402）；山东省中医药科技项目（M2023049）