Figures (6)  Tables (1)

    • Figure 1. 

      (a) Structure of the mitochondrial genome of (i) (Type 1) D. lasianthera and (ii) (Type 2) D. chrysotoxum. (b) Comparison of the mitochondrial protein-coding gene contents in nine Dendrobium species and four additional orchid species. Colors indicate single-copy (orange), double-copy (red) and lost genes (empty). (c) Mitochondrial genome maps of (i) (Type 1) D. lasianthera (ii) (Type 2) D. chrysotoxum.

    • Figure 2. 

      SSRs in the mitogenomes of four Dendrobium species. (a) Count of SSRs from six different motif types. (b) Count of different motifs acorss four Dendrobium species. (c) Count of tetra-nucleotide SSRs in four Dendrobium species.

    • Figure 3. 

      Length of dispersed repeats of the mitochondrial genome in four Dendrobium species.

    • Figure 4. 

      Synteny among the mitochondrial genomes of four Dendrobium species. Interspecific mitogenomic synteny is indicated by homologous regions. The scale is shown on the outer arcs, with intervals of 70 kb.

    • Figure 5. 

      Intracellular gene transfer in (a) D. lasianthera, (b) D. tangerinum, (c) D. huoshanense and (d) D. chrysotoxum. Mitogenomes are shown in orange, plastomes are showing green, and the color arcs within the circular ring represent homologous segments between the mitogenome and plastome.

    • Figure 6. 

      Phylogenetic relationships resolved from 33 conserved DNA sequences of protein-coding genes (PCGs) in complete mitogenomes from 29 species in nine families (Orchidaceae, Iridaceae, Amaryllidaceae, Poaceae, Typhaceae, Arecaceae, Araceae, Butomaceae and Brassicaceae) in angiosperms. The number at each node is the bootstrap support value.

    • Species D. lasianthera D. tangerinum D. huoshanense D. chrysotoxum
      Size (bp) 485,249 535,423 773,326 568,767
      Total GC content 44.7% 43.8% 44.3% 44.0%
      Coding GC 44.1% 44.3% 43.3% 43.0%
      Non-coding GC) 43.2% 43.0% 43.6% 42.8%
      Genes 65 65 60 61
      tRNA 23 25 21 22
      rRNA 3 3 3 3
      Protein-coding genes 39 37 36 36

      Table 1. 

      Features of four Dendrobium mitogenomes.