Acorus calamus Linn. (Family: Acoraceae) commonly known as sweet flag or sweet grass is an important perennial littoral medicinal plant widely used in Indian System of Traditional Medicine since times immemorial. Four cytotypes, viz., diploid (2n=2x=24), triploid (2n=3x=36), tetraploid (2n=4x=48) and hexaploid (2n=6x=72) are found world-wide, of which, only two cytotypes, viz., diploid and triploid are found in Manipur, North-east India. Different cytotypes show great morphological variabilities and wide variations in chemical composition of essential oils in the rhizomes and leaves. These cytotypes, through literature survey, are used for their anti-spasmodic, anti-diarrhoeic, carminative, anti-helminthic, anti-depressant and CNS anxiolytic properties, as tonic, stimulant and aphrodisiac, for treating rheumatism, toothache and respiratory ailments. The aromatic oils are used for flavouring alcoholic beverages and as fragrances in perfumes and sacred oils. The crude extract can prevent acrylamide-induced limb paralysis, decreased glutathione content and glutathione transferase activity, and increased dopamine receptor in corpus striatum, possess anti-oxidant properties, prevent noise stress-induced changes in rat brain and significant hypolipidemic activities. Bioactive compounds present in Acorus calamus are acorin, α- and β-asarone, asaryldehyde, caryophylene, isoasarone, methyl isoeugenol and safrol. Of the major components present in the essential oil, the content of β-asarone varies with ploidy level. Triploid accessions investigated from Manipur contain 7-7.85% β-asarone as against 73-88% in tetraploid accessions from other parts of India. Since the diploid cytotype is characterized by the absence of β-asarone which has known toxic effect and can cause chromosomal aberration, mutation and various types of cancer, it has attracted considerable interest in pharmaceutical industry. Traditional Chinese prescriptions suggest that Acorus calamus extracts possess beneficial effects on memory disorder, learning performance and anti-aging effect. 

We have studied diploid (2n=24) and triploid (2n=36) cytotypes, and developed clonal propagation protocols using dual-phase culture system, and also produced microrhizome technology as potential propagation strategies which have great relevance in meeting conservational agenda as well as sustainable developmental priorities. Acorus calamus accessions across 19 different populations have been investigated on the basis of ploidy level. Randomnly amplified polymorphic DNA (RAPD) and inter specific sequence repeat (ISSR) molecular markers have been employed for revealing genetic variability of the species. Amplification of genomic DNAs using 32 primers yielded 238 bands of which 84 bands are polymorphic revealing 35.3% polymorphism. The average polymorphic information content obtained are 0.19 and 0.22 respectively. Marker index (RAPD 0.078; ISSR 0.106) and resolving powers (RAPD 0.22; ISSR 0.26) indicated that ISSR markers are more efficient than RAPD markers. Similarity matrix has been used to construct dendrogram based on UPGMA analysis and grouped accessions into two clusters. The dendrogram clusters the accessions as per the ploidy level. Some of these interesting insights shall be presented in detail.

Prof Sharma retired as Professor (HAG) after contributing forty years of distinguished service to the Manipur University. He received MSc from Banaras Hindu University, MPhil and PhD from Jawaharlal Nehru University, New Delhi. Since 1976, he has been teaching at the Department of Life Sciences, Manipur University where he became a Professor of Genetics & Radiation Biology in 1992, and Professor (HAG) in 2014. He was Head, Department of Life Sciences (1994-96), Director, Department of Biotechnology (2006-07), Dean, School of Sciences (2009-10), Dean, School of Life Sciences (2010-12) and Co-ordinator, UGC-Centre of Advanced Study in Life Sciences, MU (2012-15). Recipient of various scholarships and fellowships throughout his career, Prof Sharma received UGC Junior/Senior Research Fellowships (1973-76), UGC Teacher Fellowship (1979-82), Commonwealth Academic Staff Fellowship (1989-90), Indo-Italian Cultural Exchange Programme Fellowship (2000) and UGC- BSR Faculty Research Fellowship (2016-19). He worked as a Post-Doctoral Research Fellow at Department of Biochemistry, Brunel University, London in Free Radical Biology (1989-90). During the Indo-Italian Programme (2000), he was a Senior Visiting Professor at National Institute of Food & Nutrition Research, Rome where he delivered a series of scientific lectures on food irradiation, free radicals and dietary anti-oxidants. 

Member of various scientific bodies in India and abroad, Prof Sharma has eighty eight publications in international and national journals of repute, viz., Radiation Botany, Radiation Research, Environmental & Experimental Botany, Methods in Enzymology, HortScience, International Journal of Radiation Biology, Cytobios, Microbios Letters, Biomedical Letters, Trends in Radiation & Cancer Biology, Journal of Environmental Pathology, Toxicology & Oncology, Journal of Food, Agriculture & Environment, The Orchid Review, Scientia Horticulturae, Garden’s Bulletin, The Orchids, Euphytica, Biologia Plantarum, Acta Horticulturae, Notulae Botanica, European Journal of Medicinal Chemistry, Journal of Bamboo and Rattan, The Open Plant Science Journal, Biotechnology, Horticultural and Environmental Biotechnology, Journal of Crop Science and Biotechnology, European Journal of Medicinal Chemistry, Radiation and Environmental Biophysics, Journal of Herbs, Spices & Medicinal Plants, Journal of Free Radicals and Anti-oxidants, Free Radicals in Biology and Medicine, International Journal of Pharmacognosy & Phytochemical Research, Indian Journal of Experimental Biology, Indian Journal of Biochemistry and Biophysics, Indian Journal of Biotechnology, Indian Journal of Radiation Biology, Indian Journal of Chemistry, Current Science and proceedings of various national/international conferences/congresses. He has delivered twenty four invited/plenary/session/key note lectures in several international conferences held in Singapore Botanic Garden, Chiang Mai University (Thailand), INRAN, Rome (Italy), Wageningen University, Leiden (Netherlands), Imperial College, London (UK), JB Hynes Convention Center, Boston (USA) and India besides chairing in a number of scientific sessions. 

He has supervised eleven MSc/MPhil dissertations and nineteen PhD theses in the areas of Genetics, Plant Tissue Culture and Radiation Biology. He has conducted several research projects sponsored by funding agencies such as University Grants Commission, Department of Science & Technology, Department of Atomic Energy, Department of Biotechnology, Indian Council of Medical Research, Department of Environment, Government of India. Prof Sharma was keenly involved in proposing and defending the establishment of the DBT Institute of Bioresources & Sustainable Development (IBSD), Imphal and associated with the production of educational films for IGNOU and UGC country-wide classroom. His film, Tupi’s Nanas (a film on pineapples) won him the Best Resource Person Award (1997) in Science, Mathematics & Engineering at the Xth UGC-CEC Audio-visual Competition, New Delhi. Prof Sharma was the recipient of the prestigious Birbal Sahni Centenary Award (2009) for outstanding contributions in the field of Life Sciences, particularly Radiation Biology. Prof Sharma has edited a book entitled, Current Topics in Redox Biology published by McGraw Hill Education, New Delhi and New York (2015).