The chloroplast DNA (cpDNA) of P. equestris was determined and compared to that of P. aphrodite. The two moth orchids showed similar genome size, structure, gene order, codon usage, and AT content. The ndh genes were either lost or nonfunctional in two endemic moth orchids. The rate of interspecies variation between moth orchids was 0.74% (1107 sites) for single nucleotide substitution and 0.24% for insertions (161 sites; 1388 bp) and deletions (189 sites; 1393 bp). The intergenic spacers were the most divergent, followed by introns, and were used for the evaluation of molecular markers. Fifteen out of 27 cpDNA regions were highly variable among the moth orchids. The rps16-trnQ marker showed the best discriminatory power: 15 endemic moth orchids could be successfully separated into 13 groups. From the sequences of the 7 selected cpDNA regions, the rps16-trnQ intergenic spacer was the best DNA barcode: 19 endemic moth orchids could be completely distinguished.
All Science Journal Classification (ASJC) codes
- Biochemistry, Genetics and Molecular Biology(all)
- Agricultural and Biological Sciences(all)
- Environmental Science(all)