Molecular identification of Taihangia rupestris Yu et Li, an endangered species endemic to China

Abstract The narrow range of distribution and special habitat of Taihangia rupestris Yu et Li have rendered it endangered. The absence of a reliable taxonomic tool increases the difficulty of identifying this species. Molecular species identification with DNA barcoding is a promising tool for the investigation and conservation of both endangered plant and animal species. This approach can facilitate species-level identification even if only a small fragment of the organism, flowers or fruits, at any developmental stage is present. Therefore, this study was undertaken to develop DNA barcodes of the two subspecies of the genus Taihangia by using the loci from both the chloroplast and nuclear genomes. The five loci tested for their potential as effective barcodes were Rubisco large subunit, maturase K, psb A- trn H, internally transcribed spacer ( ITS ), and ITS2 . Six parameters were calculated to analyze intraspecific variation and interspecific divergence. The neighbor-joining tree on the basis of the psb A- trn H sequence can clearly discriminate the two subspecies of T. rupestris , namely, T. rupestris var. ciliate and T. rupestris var. rupestris. These results can advance our understanding of Taihangia , and increased number of studies should be undertaken in the future to clarify this issue. Such recognition will facilitate the preservation of the genetic diversity in Taihang mountains.