Comparative and phylogenetic analyses of 26 Magnoliaceae species based on complete chloroplast genome sequences

Magnoliaceae is a family of dicotyledonous plants with primitive flowers and is one of the oldest families of flowering plants. In this paper, the chloroplast genomes of 26 species of Magnoliaceae were contrasted and compared to help clarify the relationship between them. The size of the 26 Magnoliaceae chloroplast genomes ranged from 158,177 bp to 160,183 bp, and approximately 1298 simple-sequence repeats were detected. For long repeat sequences, 197 repeat loci, including 144 forward repeats, 52 palindromic repeats, and 1 reverse repeat, were detected. In four species, an abnormal gene, rpl22, contained premature stop codons. Moreover, three non-coding regions (ccsA-ndhD, ndhD-psaC, and trnH-psbA) with a nucleotide diversity (Pi) value greater than 0.02 and six coding genes (ycf1, petL, matK, psbT, rps19, and ndhF) with a Pi value no less than 0.008 were identified (this information is important in resolving relationships within the Magnolia genus). The ML (maximum likelihood) and BI (Bayesian inference) trees had the same topological structures, with high support rates among 20 species, i.e., excluding Magnolia dealbata, M. pyramidata, M. conifera, M. glaucifolia, M. dealbata, and M. pyramidata. On the whole, these data represent valuable resources for Magnoliaceae chloroplast genomics and will be useful in future phylogenetic studies.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author