目的 解析广丰千金薯Dioscorea opposite叶绿体基因组信息序列特征和确定其在薯蓣属的系统位置。方法 利用高通量测序技术对广丰千金薯叶片进行核基因组重测序，并利用生物信息学相关工具对组装得到的叶绿体基因组进行注释、序列特征和系统发育分析。结果 广丰千金薯叶绿体基因组长度为153 293 bp，注释到84个CDS基因、31个tRNA基因和8个rRNA基因。广丰千金薯叶绿体基因组中共检测到45个SSR位点，多为单碱基（A/T）重复类型。广丰千金薯叶绿体基因组共鉴定到61个长重复序列，包括16个正向重复、21个回文重复、14个反向重复、10个互补重复。广丰千金薯叶绿体基因组高变区主要分布在LSC和SSC区域，基因间隔区matK-tnaQ-UUG、atpl-rps2、psbl-trnS、rpl32-ndhF、ndhD-ccsA、trnE-UUC-trnT-GGU、trnS-GCU-trnG-UCC、rps2-rpoC2以及基因ycf1变异率最高。广丰千金薯叶绿体基因组的密码子偏性较弱。广丰千金薯叶绿体基因组密码子偏好以A、U结尾。广丰千金薯叶绿体基因组密码子使用偏性很大程度上受自然选择的影响，而受突变压力的影响小。广丰千金薯叶绿体基因组的最优密码子共16个，即UUA、UCU、GAU、GGA、AAU、CAU、GUA、CAA、GAA、CCU、GUU、AUU、CGA、CUU、UUU、AGU。广丰千金薯与野脚板薯Dioscorea polystachya NC_037716聚为一小支。结论 广丰千金薯与野脚板薯NC_037716亲缘关系较近。首次采用生物信息学分析方法对广丰千金薯叶绿体基因组的序列特征及密码子使用偏好性进行了分析，结果可为薯蓣属植物的遗传多样性分析提供理论依据。

Objective To analyze the chloroplast genome sequence characteristics of Dioscorea opposite Thunb. cv. Guangfeng Qianjinshu and determine its systematic position in the Dioscorea genus. Methods The nuclear genome of the leaves of D. opposite Thunb. cv. Guangfeng Qianjinshu was re-sequenced by high-throughput sequencing technology, the assembled chloroplast genome and its sequence characteristics and phylogeny were annotated and analyzed using bioinformatics related tools. Results The chloroplast genome length of D. opposite Thunb. cv. Guangfeng Qianjinshu was 153 293 bp, and 84 CDS genes, 31 tRNA genes and eight rRNA genes were annotated. A total of 45 SSR loci were detected in the chloroplast genome of D. opposite Thunb. cv. Guangfeng Qianjinshu, most of which were single base (A/T) repeats. A total of 61 long repeat sequences were identified from the chloroplast genome of D. opposite Thunb. cv. Guangfeng Qianjinshu, including 16 forward repeats, 21 palindrome repeats, 14 reverse repeats, and ten complementary repeats. The hypervariable regions of chloroplast genome of D. opposite Thunb. cv. Guangfeng Qianjinshu were mainly distributed in LSC and SSC regions, and the gene spacer matK - tnaQ-UUG, atpl - rps2, psbl - trnS, rpl32 - ndhF, ndhD - ccsA, trnE-UUC - trnT-GGU, trnS-GCU - trnG UCC, rps2 - rpoC2 and gene ycf1 had the highest mutation rates. The codon bias of chloroplast genome of D. opposite Thunb. cv. Guangfeng Qianjinshu was weak, whose codon preference of chloroplast genome ended with A and U. Codon usage bias of chloroplast genome of D. opposite Thunb. cv. Guangfeng Qianjinshu was largely affected by natural selection, but was less affected by mutation pressure. There were 16 optimal codons in the chloroplast genome of Guangfeng Qianjinshu, namely UUA, UCU, GAU, GGA, AAU, CAU, GUA, CAA, GAA, CCU, GUU, AUU, CGA, CUU, UUU, AGU. D. opposite Thunb. cv. Guangfeng Qianjinshu and D. polystachya NC_ 037716 was gathered into a small branch. Conclusion The genetic relationship between D. opposite Thunb. cv. Guangfeng Qianjinshu and D. polysachya NC_ 037716 was relatively close. For the first time, bioinformatics analysis methods were used to analyze the sequence characteristics and codon usage bias of the chloroplast genome of D. opposite Thunb. cv. Guangfeng Qianjinshu. The results can provide a theoretical basis for the genetic diversity analysis of Dioscorea plants.

R286.12

国家自然科学基金资助项目(31960079);江西省科技厅重点研发计划一般项目(20202BBG73010);江西省教育厅科学技术研究项目(GJJ201704);江西省现代农业产业技术体系建设专项(JXARS-13-赣东站);上饶市科技局平台载体建设项目(2020J001)