A study on molecular taxonomy of South Indian species Selaginella sweared by DNA barcoding using rbcL

Abstract

In this study, genetic polymorphisms using DNA barcoding has been performed on selected ten species of Selaginella collected form Tamil Nadu and the Hills of Kerala. The main aim of this study was to estimate a phylogenetic and evolutionary relationship between selected species of Selaginella using DNA barcoding. The genomic DNA of selected species of Selaginella was isolated and were examined for DNA polymorphisms. The method described by Sanger has been used to sequence the PCR rbcL products. The phylogenetic analysis was carried out using four methods viz., minimum evolution, neighbor joining, UPGMA and maximum parsimony. For the studied species, the PCR amplification result was good, the molecular weight range from 500 to 600 base pairs and the amplicons were sequenced. The obtained sequences were aligned, annotated and submitted in GenBank. The phylogenetic analysis of studied Selaginella species using minimum evolution, NJ and UPGMA methods showed similar trees whether maximum parsimony tree displayed varied tree. The sequence alignment results illustrated that the sequence of S. involvens, S. intermedia, S. inaequalifolia, S. wightii and S. tenera were distinct from the other studied Selaginella species viz., S. brachystachya, S. repanda, S. radicata, S. bryopteris and S. delicatula. The cladistics tree also explains the relationship between S. delicatula with and without cones. This concludes that rbcL data is most valuable for inferring phylogenetic relationship between closely related species. DNA barcoding using rbcL gene was applied to distinguish the inter-specific variation among the selected Selaginella species.