ABSTRACT
In this paper, the chloroplast psbK-psbI intergenic spacers of 18 species of Dendrobium and their adulterants were amplified and sequenced, and then the sequence characteristics were analyzed. The sequence lengths of chloroplast psbK-psbI regions of Dendrobium ranged from 474 to 513 bp and the GC contents were 25.4%-27.6%. The variable sites were 71 while the informative sites were 46. The inter-specific genetic distances calculated by Kimura 2-parameter (K2P) of Dendrobium were 0.006 1-0.058 1, with an average of 0.028 4. The K2P genetic distances between Dendrobium species and Bulbophyllum odoratissimum were 0.093 2-0.120 4. The NJ tree showed that the Dendrobium species can be easily differentiated from each other and 6 samples of the inspected Dendrobium species were identified successfully through sequencing the psbK-psbI intergenic spacer. Therefore, the chloroplast psbK-psbI intergenic spacer can be used as a candidate marker to identify Dendrobium species and its adulterants.
ABSTRACT
This paper reviewed the research developments of identification and classification ofDendrobium species based on DNA sequences from nuclear genome, mitochondrial genome and chloroplast genome. The existing documents revealed that DNA sequences used in identification ofDendrobium mainly include ITS/ITS2,LEAFY, chloroplastrbcL, matK, trnH-psbA, rpoB, rpoC1, trnL-F, rbl16, trnl intron, and mtDNA, nad1 intron2. These DNA sequences had the reference meanings in the identification ofDendrobium species. This article discussed the feasibility of complete chloroplast genome as the“super-barcode”, which provided the references for identification of medicinal plants inDendrobium.