Comparative plastomic analysis of three Bulbophyllum medicinal plants and its significance in species identification / 药学学报

ABSTRACT

italic>Bulbophyllum orchids are popular for its ornamental appearance and great medicinal values. However, there is still a lack of research on phylogenetic relationship and species identification for this genus. In this study, the plastome sequences of three medicinal Bulbophyllum orchids (Bulbophyllum affine, Bulbophyllum pectinatum, Bulbophyllum funingense) were sequenced and analyzed. After assembly and annotation, it was found that the plastomes of Bulbophyllum plants encoded a total of 108 genes, including 74 protein-coding genes, 30 tRNA genes and 4 rRNA genes. Based on the analysis of mVISTA and comparison between junctions, it was found that the plastome structure of Bulbophyllum orchids was relatively conserved, and the variation mainly existed in the non-coding regions. Phylogenetic analysis showed that Bulbophyllum orchids were closely related to Dendrobium orchids. SSR analysis of Bulbophyllum showed that most SSRs were located in the intergenic spacer and had the most single nucleotide repeats. In addition, based on the comparative analysis of non-coding sequences, a total of 10 high-variability sequences were screened out, among which the combination of five non-coding region sequences, including psbI-trnS, psbC-trnS, clpP-ex1-psbB, psaJ-rpl33, rpl33-rps18, had the highest sequence variability and could be used in the species identification study of medicinal plants of Bulbophyllum. In conclusion, this study provides a theoretical basis for phylogenetic relationship and species identification of Bulbophyllum orchids through the comparative analysis of plastome sequences of three medicinal plants of the genus Bulbophyllum.