Phylogenetic relationship and evolution analysis of the peony Paeonia species using multi-locus deoxyribonucleic acid (DNA) barcodes

摘要

Paeonia?is a phylogenetically and taxonomically complex group. In this study, two chloroplast coding region of the?matK?and?rbcL?genes, two intergenic spacers, 5’?trnK-matKand?matK-3’?trnK, the ribosomal RNA 18S and 5S genes, and the nuclear ribosomal DNA ITS gene were sequenced to study phylogenetic relationships of four?Paeonia?species. In the?matK?coding region, most nucleotide variations pointed at the divergence betweenPaeonia suffruticosa?(MO) and other three species, strongly supporting the phylogenetic evolution of section?Paeonia?and section?Moutan?in the?Paeonia?genus; the variable sites ofPaeonia lactiflora?CHA1 accession compared to CHA accession were all identical toPaeonia obovata?SHAN accession, indicating that CHA1 might be a hybrid result of CHA and SHAN. Another chloroplast coding region,?rbcL?showed lower variation rate and less phylogenetic information than the?matK?region in all four?Paeonia?species investigated in this study, while the 5S rRNA gene and nrDNA ITS region showed higher variation rate. However, combined phylogenetic relationship of all four peony species is more clearer than any single-locus one. This study would provide more sequence sources of peony species and help further understanding of the phylogenetic relationship.