Biological species are traditionally identified based on their morphological features and the correct identification of species is critical in biological studies. However, some plant types, such as seagrass, are taxonomically problematic and difficult to identify. Furthermore, closely related seagrass species, such as Halophila spp, form a taxonomically unresolved complex. Although some seagrass taxa are easy to recognize, most species are difficult to identify without skilled taxonomic or molecular techniques.
DNA barcoding is a desirable tool for medicinal product authentication. DNA barcoding is a method for species identification using short DNA sequences that are conserved within species, but variable between species. Unlike animals, there is no single universal DNA barcode locus for plants. Coding markers, matK and rbcL, and noncoding markers, trnH-psbA (chloroplast) and ITS2 (nuclear), have been reported to be suitable for the DNA barcoding of plants with varying degree of success.
Phylogenetic relationships in the Lathyrus genus were examined using cpDNA data, particularly data attributed to the “barcode” rbcL gene to construct a possible evolutionary scenario. Plant barcoding can be used to differentiate between species within a genus and to conserve DNA within the same species. We assessed the phylogeny of 29 species of Lathyrus using maximum parsimony, maximum likelihood and unweighted pair-group method and arithmetic mean. The classifications did not agree with current morphological and basic Lathyrus classification.
Some species of the genus Ochradenus are difficult to identify based on morphological markers. Similar limitations are found for biochemical markers. We developed genetic markers based on DNA sequences for Ochradenus arabicus, which is an endemic plant to Saudi Arabia, locally utilized as a medicinal shrub. The internal transcribed spacer sequence of nuclear ribosomal DNA and chloroplast (rpoB and rpoC1) markers were more informative than other chloroplast DNA markers.
DNA barcoding is currently gaining popularity due to its simplicity and high accuracy as compared to the complexity and subjective biases associated with morphology-based identification of taxa. The standard chloroplast DNA barcode for land plants recommended by the Consortium for the Barcode of Life (CBOL) plant working group needs to be evaluated for a wide range of plant species. We therefore tested the potential of the rbcL marker for the identification of wild plants belonging to diverse families of arid regions.
Fallopia multiflora, locally known as Heshouwu, is one of the most important and widely used Chinese medicinal herbs. However, there is still considerable confusion concerning its different provenances. DNA barcoding is a recent aid to taxonomic identification and uses a short standardized DNA region to discriminate plant species. We assessed the applicability of 4 candidate DNA barcodes (matK, rbcL, psbA-trnH, and ITS2) to identify populations of F. multiflora.