Application of the ITS2 Region for Barcoding Medicinal Plants of Selaginellaceae in Pteridophyta

Abstract

BackgroundSelaginellaceae is a family of nonseed plants with special evolutionary significance. Plants of the family Selaginellaceae are similarly shaped and easily confused, complicating identification via traditional methods. This study explored, for the first time, the use of the DNA barcode ITS2 to identify medicinal plants of the Selaginellaceae family.Methodology/Principal FindingsIn our study, 103 samples were collected from the main distribution areas in China; these samples represented 34 species and contained almost all of the medicinal plants of Selaginellaceae. The ITS2 region of the genome was amplified from these samples and sequenced using universal primers and reaction conditions. The success rates of the PCR amplification and sequencing were 100%. There was significant divergence between the interspecific and intraspecific genetic distances of the ITS2 regions, while the presence of a barcoding gap was obvious. Using the BLAST1 and nearest distance methods, our results proved that the ITS2 regions could successfully identify the species of all Selaginellaceae samples examined. In addition, the secondary structures of ITS2 in the helical regions displayed clear differences in stem loop number, size, position, and screw angle among the medicinal plants of Selaginellaceae. Furthermore, cluster analysis using the ITS2 barcode supported the relationship between the species of Selaginellaceae established by traditional morphological methods.ConclusionThe ITS2 barcode can effectively identify medicinal plants of Selaginellaceae. The results provide a scientific basis for the precise identification of plants of the family Selaginellaceae and the reasonable development of these resources. This study may broaden the application of DNA barcoding in the medicinal plant field and benefit phylogenetic investigations.

A large‐scale phylogeny of the lycophyte genusSelaginella(Selaginellaceae: Lycopodiopsida) based on plastid and nuclear loci

“…One plastid region (the rbcL gene) and one nuclear region [the internal transcribed spacer (ITS)] were selected based on their use in earlier studies of Selaginella and allies (Korall et al., ; Korall and Kenrick, , ; Arrigo et al., ; Gu et al., ; Saha et al., ). Most rbcL sequences were amplified with primers F1 (Fay et al., ) and 1379R originally designed by Zurawski et al.…”

Spore morphology of Selaginella (Selaginellaceae) from China and its systematic significance

“…Moreover, most morphologically similar species usually share same habitats (Zhang et al 2013). All of these factors not only make species of Selaginella difficult to identify, but also easy to be confused (Banks 2009, Gu et al 2013, Schulz et al 2013. Meanwhile, infrageneric classifications (e.g., Spring 1850, Hieronymus & Sadebeck 1901, Walton & Alston 1938, Jermy 1986) and the delimitation of species (e.g., Baker 1887, Tryon 1955, Zhang et al 2013 are always controversial in Selaginella.…”

DNA Barcoding: An Alternative for the Identification of the Medicinal Plants Employed in Mexico

“…Another molecular method, which has led to the rapid, accurate and automatic identification of plants, using DNA sequences, is called DNA barcoding, the main characteristic of this method is the use of short, standard and unique sequences of the genomic DNA for the identification of botanical species (Hao et al, 2008(Hao et al, , 2009a(Hao et al, , 2010bGao et al, 2010;Chen et al, 2010;Gu et al, 2013). The technique, identifies an unknown sample by comparison with a known reference plant material, its main application includes the identification of plants using fragments of leaves, when other plant organs are not available, as well as, the identification of individual species in mixtures.…”