Genomic characteristics and comparative analysis of chloroplast genome in Magnoliaceae

Magnoliaceae is a relatively primitive angiosperm, which is of great significance for the study of long chain of biological evolution. In this study, the chloroplast genome of Magnoliaceae was analyzed, and the codon usage pattern preference of Magnoliaceae chloroplast genome was analyzed by CondonW1.4.2 and EMBOSS. The chloroplast genome content of 63 Magnoliaceae plants was lower than 50%, and the NC value was higher than 35, indicating that the chloroplast genome codon use was weak. Based on the analysis of ENC-plot, it is indicated that the main factor affecting the use bias of chloroplast genome codon in Magnoliaceae is the influence of base mutation. There is A preference for A or T in the use of codons. The analysis of the genome structure of Magnoliaceae showed that Magnoliaceae has a typical four-segment ring structure of angiosperms, including a single copy region, a large copy region and a reverse repeat region, and the IR region of Magnoliaceae chloroplast genome showed a non-significant expansion trend. In this study, the chloroplast genome structure and codon preference of Magnoliaceae were analyzed to provide scientific basis for the accurate identification of species and germplasm resources of Magnoliaceae. The phylogenetic tree of 63 species of Magnoliaceae was established by using the maximum likelihood method to explore the phylogenetic relationships among species, and to provide scientific basis for further research on the phylogenetic relationships of Magnoliaceae.