DNA barcodes for delineating Clerodendrum species of North East India

Barbi Gogoi,S P Saikia,S B Wann

doi:10.1038/s41598-020-70405-3

Barbi Gogoi, S P Saikia + Show 1 more

Open Access

https://doi.org/10.1038/s41598-020-70405-3

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Abstract

The diversified genus of Clerodendrum with its complex evolutionary history leads to taxonomic mystification. Unlike traditional taxonomic methods, DNA barcoding could be a promising tool for the identification and conservation of Clerodendrum species. This study was attempted to develop an efficient barcode locus in Clerodendrum species of North East India. We evaluated four barcode candidates (ITS2, matK, rbcL, ycf1) and its combinations in different Clerodendrum species. The reliability of barcodes to distinguish the species were calculated using genetic pairwise distances, intra- and inter-specific diversity, barcode gap, and phylogenetic tree-based methods. The results exemplify that matK posse’s maximum number of variables and parsimony-informative sites (103/100), intra- (0.021 ± 0.001) and inter- (0.086 ± 0.005) specific divergences and species resolution rate (89.1%) followed by ITS2, ycf1, and rbcL. Among the combinatorial locus, ITS2 + matK showed the best species discrimination with distinctive barcode gaps. Therefore, we tentatively suggest that the combination of ITS2 + matK as core barcode for Clerodendrum and converted into quick response (QR) code. Hence, this finding indicates that DNA barcoding could provide consistent resources for species discrimination and resolve taxonomic controversies of the genus as well as set a preliminary assessment toward its biodiversity.

Highlights

North East India is endowed with enormous biodiversity of flora and fauna
23 Clerodendrum species were found in India, while 18 species occur in North East I ndia[3]
The success rate of polymerase chain reaction (PCR) amplification for four loci (ITS2, matK, rbcL and ycf1) were 100% and sequencing rates were maximum for matK (95.7%) followed by ycf[1] (94.6%), ITS2 (93.6%) and rbcL (90.4%) respectively (Table 1)

Summary

Introduction

North East India is endowed with enormous biodiversity of flora and fauna. Clerodendrum is a large, complex, and diversified genus that encompasses well-established pharmacological properties and its importance of ethnomedical assets was reported in many indigenous systems of m edicines[1]. 23 Clerodendrum species were found in India, while 18 species occur in North East I ndia[3]. DNA barcoding uses short standardized region of DNA sequence(s) (either nuclear or/and cytoplasmic genome) for rapid authentication of discrete species and cost-effective in n ature[7]. No authenticated report on the practice of DNA barcoding in Clerodendrum sp. We collected only 9 species of Clerodendrum from different locations of North East India, and the rest of the species were not encountered during the fieldwork as they were extremely rare and only known from a small number of locations. The DNA sequences contain long strings of characters (BSTD), CSIR-North East Institute of Science & Technology, Jorhat 785006, Assam, India. This study could lead to valuable aid in the conservation of biodiversity strategies and the improvement of the genus

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