Micromorphological Molecular Molecular taxonomy of Genus Ophioglossuml In kerala, india.

Abstract

Genus Ophioglossum is commonly called Adder's tongue or snake tongue fern owing to the shape of its tropophyll and fertile spike. It has 53 accepted species worldwide. The genus showed cosmopolitan distribution in all continents except in Antartica. The name was derived from combining two Greek words, ophios and glossa, meaning snake and tongue. Ophioglossum is a complex genus with bewildering morphological characters. The taxonomy of Ophioglossum was always confused from the past years and faced many nomenclatural issues. The genus Ophioglossum is one of the least studied genera in Kerala. It can be easily distinguished from the other genera by its tropophyll, fertile spike and rhizome. This study aims to revise the genus Ophioglossum for the first time in Kerala, India. A combined morphological and molecular analysis was carried out to solve the nomenclatural problems within the genus and to trace the evolutionary relationship among them. Extensive field explorations were conducted during 2018 – 2022. Specimens were collected. The field observations, such as habit, habitat, rhizome, nature and colour of the tropophylls were noted in the field book. Morphological analysis includes both micromorphology and macro morphology. Micromorphology mainly focused on venation pattern, stomatal characters and spore morphology. Plant materials were dried and mounted on standard herbarium sheets. Herbarium sheets of each species, including type specimen, were deposited at St. Thomas College herbarium. Distribution maps of each species were prepared for future study. Molecular analysis was carried out using chloroplast genes (rbcL-F, psbA-trnH and trnL-F). The newly generated sequences were deposited into NCBI GenBank. Phylogenetic trees were constructed based on the three primer regions. The newly generated sequences and the sequence retrieved from GenBank were used for constructing the tree. Previously there were 10 species reports from Kerala, the present study reports fourteen taxa in Kerala. Among them, Ophioglossum sp. nov. was described as a new species. O. latifolium was a new report for India and O. indicum was a new report for South India. The species status of O. raphaelianum and O. indicum was reinstated, O. madhusoodananii considered as a synonym of O. costatum and O. trilokinathii was considered as a synonym of O. rubellum. The occurance of O. lusitanicum and O. vulgatum in India was confirmed. Evaluation of the medicinal properties of genus Ophioglossum in Kerala and cytological studies on genus Ophioglossum in Kerala are the future aspects of this study.