Chi Xiaofeng, Zhang Faqi, Dong Qi, Chen Shilong
Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810008, China.
Qinghai Provincial Key Laboratory of Crop Molecular Breeding, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810008, China.
Plants (Basel). 2020 Nov 18;9(11):1605. doi: 10.3390/plants9111605.
Biebersteiniaceae and Nitrariaceae, two small families, were classified in Sapindales recently. Taxonomic and phylogenetic relationships within Sapindales are still poorly resolved and controversial. In current study, we compared the chloroplast genomes of five species ( and ) from Biebersteiniaceae and Nitrariaceae. High similarity was detected in the gene order, content and orientation of the five chloroplast genomes; 13 highly variable regions were identified among the five species. An accelerated substitution rate was found in the protein-coding genes, especially . The effective number of codons (EN), parity rule 2 (PR2), and neutrality plots together revealed that the codon usage bias is affected by mutation and selection. The phylogenetic analysis strongly supported (Nitrariaceae (Biebersteiniaceae + The Rest)) relationships in Sapindales. Our findings can provide useful information for analyzing phylogeny and molecular evolution within Biebersteiniaceae and Nitrariaceae.
刺茉莉科和白刺科这两个小科最近被归入无患子目。无患子目中的分类学和系统发育关系仍未得到很好的解决且存在争议。在当前的研究中，我们比较了刺茉莉科和白刺科五个物种（……此处原文缺失物种名称……）的叶绿体基因组。在这五个叶绿体基因组的基因顺序、内容和方向上检测到高度相似性；在这五个物种中鉴定出13个高度可变区域。在蛋白质编码基因中发现了加速的替换率，尤其是……此处原文缺失具体基因……。有效密码子数（EN）、奇偶规则2（PR2）和中性绘图共同表明密码子使用偏好受突变和选择的影响。系统发育分析强烈支持无患子目中白刺科（刺茉莉科 + 其他类群）的关系。我们的研究结果可为分析刺茉莉科和白刺科的系统发育和分子进化提供有用信息。
