Molecular authentication and differentiation of Dendrobium species by rDNA ITS region sequence analysis

Abstract

Owing to their significant medicinal and edible values, the natural Dendrobium species have underdone over-collection and habitat destruction, and cultivated species emerged for candidates. However, these Dendrobium plants are similar in shape to be easily confused, leading to extreme difficulties for identification based on their morphological and chemical features. In this study, the rDNA ITS region sequence analysis was developed for rapid and accurate identification of thirteen wild and cultivated Dendrobium species belonging to two sections Formosae and Chrysotoxae . By cloning and sequencing the rDNA ITS region genes from 13 Dendrobium species, the phylogenetic relationships among them were analyzed. Results showed that the variation of the ITS region, together with the lengths and Guanine and Cytosine contents of ITS, 5.8s rDNA, ITS1 and ITS2 sequences occurred in the tested Dendrobium species, and which from section Chrysotoxae was higher than that from section Formsae . Phylogenetic analysis based on neighbor-joining and maximum p-arsimony trees indicated that the Dendrobium species of sections Formosae and Chrysotoxae could be well divided into two groups. A majority of Dendrobium species exhibited distinctive ITS2 secondary structures, while for those with close genetic relationships were similar. Therefore, the ITS2 region sequence analysis is simple, quick, and highly reliable that can be used as an effective tool for molecular identification and classification, as well as the reconstruction of the phylogeny of wild and cultivated Dendrobium species belonging to different sections.

Molecular Identification and Evaluation of the Genetic Diversity of Dendrobium Species Collected in Southern Vietnam

“…Among those barcoding regions, ITS was the most commonly used. [2,8,9,14,15,25,[36][37][38][39]. Our results again confirmed the effect of ITS in the evaluation of genetic diversity and the identification of Dendrobium species not only in Southern Vietnam but also in other habitats.…”

“…ITS was also used in previous studies on identification of Dendrobium species, among which some studies focused on medicinal species for distinguishing herbals and their adulterants [13,14]. In a previous study of Tran et al (2018) [15], 19 out of 23 Vietnamese Dendrobium species (82.61%) were identified using the ITS marker (Appendix E).…”

“…Many works have proved that the ITS region (Internal Transcribed Spacer) contains many genetic differences, so it is used to classify species and study relationships [10,11], particularly in Dendrobium [8,12]. The ITS2 region has been assessed as being able to clearly distinguish between Dendrobium species [13,14]. Two matK and rbcL regions have also been identified as being able to identify species of the genus Dendrobium [4,10].…”

Multiplex DNA methylation profiling by ARMS-PCR for body fluid identification

“…However, the previous methods have many disadvantages to test the expression of the DNA methylation markers due to the complicated process, high cost, inaccurate results and so on. According to the previous researches, we concluded that ARMS-PCR technique is a classical and well-developed method to genotype SNPs [4]. The principle of this technique to detect DNA methylation is to design two forward allele-specific primers that can target methylation status and unmethylation status, respectively.…”

Micromorphology of Labellum in Selected Dendrobium Sw. (Orchidaceae, Dendrobieae)

“…Unfortunately, there is still little information on pollination of the Dendrobium species. Many species of Dendrobium are morphologically very similar to each other, however, some species have overlapping morphological differences that may result in misidentifications [ 6 , 7 ]. In this case, the classical methods of identification that rely on distinguishing characteristic features visible to the naked eye are not sufficient.…”