目的 探究棘豆属Oxytropis物种密码子使用模式及影响因素。方法 基于棘豆属9个代表物种的叶绿体基因组数据，采用CodonW1.4.2、SPSS23等软件分析密码子偏好性。结果 棘豆属9个代表物种密码子的不同位点GC含量差异较大，均小于50%，GC₁＞GC₂＞GC₃；碱基组成与密码子适应指数（codon adaptation index，CAI）、密码子偏好指数（codon bias index，CBI）、密码子使用频率（frequency of optional codons，FOP）等密码子参数存在显著正相关；棘豆属9个代表物种有效密码子数大于35，偏好性较弱；ENC-plot、PR2-plot和中性绘图分析显示，自然选择是影响棘豆属物种密码子偏好性的主要因素；9个代表物种鉴定到23个最优密码子，均以A/U结尾；系统发育和聚类分析表明，棘豆属物种具有明显的属内分化，黄花棘豆和甘肃棘豆的亲缘关系较近。结论 棘豆属9个代表物种的密码子偏好性较弱，自然选择是影响棘豆属物种密码子偏好性的主要因素，为棘豆属物种遗传进化研究提供了重要参考数据。

Objective To explore the usage pattern and influencing factor of codons in Oxytropis species.Methods Based on the chloroplast genome data of nine representative species from Oxytropis, software such as CodonW1.4.2 and SPSS23 were used to analyze codon bias..Results The GC content of different codon sites from nine representative species of Oxytropis was significantly different, all of which were less than 50%, and GC₁ > GC₂ > GC₃. There was significantly positive correlation between the base composition and codon parameters such as codon adaptation index(CAI), codon bias index(CBI) and frequency of optional codons (FOP). The effective number of codons in nine representative species of Oxytropis was greater than 35, and the codon preference was weak. ENC-plot, PR2-plot and neutral plot analyses showed that natural selection was the main factor affecting codon preference of Oxytropis. A total of 23 optimal codons were identified from nine representative Oxytropis species, which ended in A/U. Phylogenetic and cluster analyses showed that the Oxytropis species had obvious intra-genus differentiation, and Oxytropis ochrocephala and Oxytropis kansuensis had the closest relationship.Conclusion The codon preference of nine representative Oxytropis species was weak, and natural selection was the main factor affecting the codon preference of Oxytropis. This study provides the important reference data for the genetics and evolution of the Oxytropis species.

R286.12

青海省重大科技专项（2023-SF-A5）；2023年中央林业草原生态保护恢复资金野生动植物保护项目（QHSY-2023-016）；青海省省财政林业改革发展资金林草新技术推广项目（QSCZ-2023-001）