Optimization of Protocols for the In Vitro Multiplication and Conservation of Acorus calamus, an Endangered Medicinal Plant (original) (raw)

A. calamus L. is a critically endangered (FRLHT, 2000), semi-aquatic plant of temperate and sub-temperate regions. A. calamus, from the family Araceae, has been valued for its rhizome and fragrant oils, which is being used medicinally to cure diarrhoea, dysentery, digestion, abdominal obstruction and colitis. For rare, endangered and threatened (RET) species that are in decline, in situ conservation may not give adequate support. Biotechnology supports ex situ conservation programs, besides complementing conventional methods, have the potential to broaden the genetic base in species demanding high priority. Acorus calamus rhizome has been used to initiate aseptic cultures, which is a prerequisite for in vitro conservation. The sterile explants were cut to appropriate size and inoculated into Murashige and Skoog medium (MS full strength and half strength concentration) with and without Naphthylacetic acid (NAA) and Benzylaminopurine (BAP). The explants that responded were transferred into MS medium with BAP and NAA for multiplication and into Murashige and Skoog (MS) medium devoid of growth regulators for medium-term storage (under standard culture conditions). These cultures were incubated at 26±2°C with 31.55 μm-2 s-2 light intensity. For in vitro growth studies, parameters observed include number of shoots, shoot length, number of roots, made at intervals of 1 month, 3 months and 6 months, to establish sub-culture frequency and storage period. Rooted vitro plantlets were hardened successfully using 'Soilrite', which was found to be the best hardening medium, with ca. 99% success. In vitro established cultures of Acorus calamus were relocated to chambers having reduced light and temperature conditions (reduced temperature of 10°C and reduced light of intensity of 2.97 μm-2 s-1) to study the effect of storage. Protocols developed for large-scale propagation and in vitro conservation will be discussed. INTRODUCTION A. calamus L. is a critically endangered (FRLHT, 2000), semi-aquatic plant of temperate and sub-temperate regions. It is distributed in damp and marshy places throughout India up to 6000 feet in the Himalayas, Kashmir, Manipur and Naga Hills, Sri Lanka, Eurasia and America. It was thought to be indigenous to India but is originally native of Europe. A. calamus has been valued for its rhizome and fragrant oils, which is being used medicinally to cure diarrhoea, dysentery, digestion, abdominal obstruction and colic. It also helps in clearing speech, improves memory and intellect, infantile fever, cough, bronchitis and asthma, also used in various kinds of cancers and for treating flatulence, diarrhoea and dysentery. It is used in alcoholic beverages, as a fragrant essence in perfumes and oils, and for insecticidal, antibacterial and antifungal properties and also finds its use in Ayurveda and Siddha systems of medicine (Kritikar and Basu, 1935). Due to indiscriminate and improper management strategies, the plant species stand vulnerable in Karnataka and Tamil Nadu and endangered in Kerala, according to the threat status of red-listed plants (Rajasekharan and Ganeshan, 2002). Tissue culture and cryopreservation