Characterization of the complete chloroplast genome of Gastrochilus sinensis (Orchidaceae, Epidendroideae), a beautiful epiphytic orchid from China

Abstract

Gastrochilus sinensis is a beautiful epiphytic orchid with high ornamental value. In this study, the first complete chloroplast genome sequence of G. sinensis was determined using next-generation sequencing (NGS). The de novo assembled chloroplast genome was 148,020 bp in length, including a pair of inverted repeat regions (IRs; 25,987 bp), a small single-copy region (SSC; 11,045 bp), and a large single-copy region (LSC; 85,001 bp). The chloroplast genome encodes 109 unique genes, including 75 protein-coding genes (PCGs), 30 tRNA genes, and four rRNA genes. The total GC content of the chloroplast genome was 36.8%. The phylogenetic analysis showed a close relationship between G. sinensis and G. formosanus species. The complete chloroplast genome provides fundamental information for genetic diversity and phylogenetic relationships in Gastrochilus.

Keywords: Gastrochilus sinensis; chloroplast genome; phylogeny.

Figure 1.

Flowering plant image of Gastrochilus sinensis (this unpublished photo, taken in Sanjiang, Wenchuan County, Sichuan Province, China by Mr. Yuehong Cheng, is used with permission).

Figure 2.

The circle map of complete chloroplast genome of Gastrochilus sinensis. The map was generated by CPGView. Genes located on the inner and outer of circle are transcribed clockwise and anticlockwise, respectively. The dark grey inner circle indicates GC content. Large single-copy (LSC), small single-copy (SSC), and inverted repeats (IRA and IRB) are indicated in the inner layer. The functional classification of the genes is provided in the bottom left corner.

Figure 3.

The ML phylogenetic tree for Gastrochilus sinensis based on 20 chloroplast genomes in Aeridinae. The accession numbers of used sequences follow the species names, and the newly sequenced genome is shown in red font.