Phylogenetic and Mutation Points Analysis of Sophora japonica cv. jinhuai Based on DNA Barcoding Sequences / 中国实验方剂学杂志

ABSTRACT

ObjectiveTo conduct phylogenetic analysis of internal transcribed spacer 2 （ITS2） and chloroplast gene segments including psbA-trnH， rbcL， and matK of Sophora japonica cv. jinhuai resource samples from different geographical sources， and to explore the genetic diversity of S. japonica cv. jinhuai. MethodPolymerase chain reaction （PCR） method was used to amplify the nucleic acid sequences of ITS2， psbA-trnH， rbcL， and matK of S. japonica cv. jinhuai. Neighbor joining （NJ） method was used to construct phylogenetic trees， and Kimura 2-Parameter （K2P） model was used to calculate the genetic distance of different samples. MEGA and BIOEDIT softwares were applied for mutiple alignment and analysis of ITS2， psbA-trnH， rbcL， and matK sequences of S. japonica cv. jinhuai. ResultThe lengths of ITS2 sequence were 278-279 bp. The lengths of psbA-trnH were 289 bp. The lengths of rbcL sequence were 673 bp. The lengths of matK sequences were 786-792 bp. There were 3 mutation points in ITS2 and psbA-trnH， no mutation point in rbcL， and 13 mutation points in matK. The samples of S. japonica cv. jinhuai were clustered into two groups based on the phylogenetic tree constructed by ITS2 sequences. The sample of seedling tree in Baibao was clustered into one group， while the other 25 samples were clustered into another group. For the psbA-trnH sequence， the success rate of PCR amplification of 28 samples of S. japonica cv. jinhuai was 100%. The 28 samples of S. japonica cv. jinhuai were clustered into three groups based on the clustering results of psbA-trnH sequence. The sample of seedling tree in Shaoshui was clustered into one group. The five samples of grafting tree and seedling tree in Miaotou， grafting trees in Jiantang， Wenqiao， and Daxu， and seeding tree in Xianshui were clustered into one group. The other 21 samples were clustered into another group. The 26 samples of S. japonica cv. jinhuai were clustered into two groups based on the phylogenetic tree constructed by matK sequences. The sample of seedling tree in Xianshui was clustered into one group， while the other 25 samples were clustered into another group. The clustering results of the rbcL sequence of S. japonica cv. jinhuai could not distinguish 28 resource samples. The phylogenetic tree constructed by the combined sequence of ITS2+psbA-trnH+rbcL+matK divided S. japonica cv. jinhuai resource samples into 4 groups. The 13 samples of seedling trees in Qiyang， Daoxian， Miaotou， Shaoshui， Shitang， Xianshui， Jiantang， and Xiangli， and grafting trees in Qiyang， Miaotou， Yongsui， Wenqiao， and Yangtang were clustered into one group. The sample of seedling tree in Wenqiao was clustered into one group. The sample of seedling tree in Daxu was clustered into one group. The remaining samples were clustered into another group. ConclusionPhylogenetic and mutation analysis provide the theoretic foundation to investigate the evolution of the resources of S. japonica cv. jinhuai， and evaluate their genuineness. The results of mutation points can be used to identify the related S. japonica cv. jinhuai resources. The findings of this study show that the combination of different gene sequences has an optimal effect on plant identification.