Author

Hit K. Goswami

Abstract

This paper intends to emphasize the importance of Poly--trait diagnostic approach (Ptda) for the diagnosis of any species. The genus Ophioglossum in particular which is known to possess 2n=1450 + 10 microchromosomes as the highest chromosome number among all living organisms, has been discovered to exhibit interspecific and intraspecific chromosomal variations thereby declaring chromosome number of very little importance for species diagnosis. Also new natural hybrids are being discovered from India and other countries which have been exhibiting too many variations in gross morphology of lot many species. Thus, this is becoming almost mandatory to observe all possible morphological features of leaf, corm and spike and must also observations be made on some biochemical parameters. Additional features which offer reliable diagnosis are comparative molecular phylogenetic studies on rbcL and ther chloroplast genes along with SEM studies on spore morphology. Based on such comprehensive studies over several years some highly exciting inferences have been obtained. The family ophioglossacea known to comprise of Ophioglossum, Botrychium, Helminthostachys, Mankuya now also has phylogenetically distinct three genera raised by Zhang and Zhang (viz.: Goswamia, Haukia, and Whittieria) raising the total to seven (07) genera. According to molecular phylogenetics, all are deeply diverged from the rest as demonstrated by the long branches or numerous molecular synapomorphies of each of them..
Our poly--trait diagnosis approach ( Ptda) investigating on all above parameters have not only authenticated diagnosis of species described from India but also assert that the most reliable morphological features are SEM of spores to exhibit exine ornamentation and shape and size of corms and number of roots. This revised study indicates that conventional Ophioglossum plants with bulbous corm / rhizome with bulk of roots have to be identified as Goswamia Zhang and plants with small, linear corm with a few roots as Ophioglossum L.

Pages: 100-108

Doi Number 10.5958/2455-7218.2023.00003.7

Keywords Ophioglossaceae, Evolutionary significance of Ophioglossum and Goswamia; Multidiagnostic approach fo