Costus speciosus (Koen ) Sm medicinal important plant belong to family Zingiberaceae. All plant parts of Costus speciosus have different uses so demand of this plant increased day by day .So now a days Costus speciosus become endangered species. Tissue culture technique play an important role to conserve the endangered species.Different concentration of various phytohormones auxin,cytokinin,gibberellins directly effect on invitro regeneration of Costus speciosus.The ratio of auxin and cytokinin hormone in media are totally responsible for root and shoot initiation. Auxin are useful for the formation of roots. Cytokinin promote cell division and responsible for shoot regeneration. Different auxins like IAA,NAA and cytokinins like BAP,Kinetin etc. This type of conservation method saving the plant from extinction . The plant are useful as an ornamental purpose and medicinal point of view.The rhizome are the main source of diosgonin . It is also used for diabetes and jaundice. The root extract is useful in fever,cough ,skin disease and snake bites. The important morphological applications of plant tissue culture in micropropagation ,small amounts of tissue can be used to raised plantlets due to the presence of totipotency capacity .
Materials and methods
Costus speciosus plant collected from Vindhya herbal , Bhopal. Rhizomes were washed thoroughly in Tween -20 for 15 min.,and then washed under running tap water for 2 -3 hrs. Whole rhizome were surface decontaminated with 70% ethanol and 0.1% Hgcl2. Rhizomes cut into small pieces and inoculate in MS Media containing with growth hormones. MS medium was used as basal medium and media was supplemented with sucrose and agar . Different phytohormones at different concentration were added to the medium. The ph of the media was adjusted to 5.8 before being autoclaved at 121 0C for 20 min. and 15 lbs sq inch pressure. Explant is the starting material for micropropagation. Specific medium selection is necessary with special reference to concentration of particular growth hormones. Plant growth hormone added as per requirement and dissolved properly. Different concentration of BAP and NAA were used for shoot induction and study the effect of different hormones on regeneration.All the cultures were incubated at 25 .C under white fluorescent tube. The initiated shoots can be subcultured . The normal period between subcultures is 3 weeks and during this time the number of shoots available for subculture.
Shoot induction Experiment
The effect of season,age of explants and the effect of various hormones on initiation of shoots were studied simultaneously. For these studies the sterile rhizomes were inoculated on Murshige and Skoog (1962) basal medium supplemented with cytokinin like BAP and Auxin NAA in different concentration . This medium containing with sucrose and agar also.
Results and observation
In preliminary studies conducted it was found that the response of the explants in culture was dependent on the age of the explants and season of inoculation. Rhizome used as a explants shows better results during the month of November to January were more vigorous and responded more.The time period of the treatment of surface disinfectant (0.1% Hgcl2 ) was standardized from 2-3 minutes for explants.
The inoculated culture were maintained at 250 C and 16 hour photoperiod.After 25 days small shoot initiate from the rhizome .The best response was observed in the medium supplemented with BAP combination with NAA. In these media the explants induced healthy and vigorous shoots which was elongated to 4-5 cm in 30-50 days
The present work has shown that cutting the rhizome into segments and cultured them on to suitable medium supplemented with phytohormones can initiate the explants. The success was not achieved when the rhizome segment were cultured on MS media. Initiation was observed when MS media supplemented with NAA and BAP.
Conclusion
In India several important and necessary steps have to be taken up for its propagation . In vitro studies on Costus speciosus results in fast regeneration of this plant and thus to fulfill the growing demand of Costus speciosus diosgonin. Due to the medicinal importance of rhizome, Costus speciosus is rapidly disappearing from its natural habitat. Therefore its important to develop methods for the propagation and and conservation of this endangered species.
References
Chaturvedi, H. C., Misra, P., Jain, M., 1984. Proliferation of shoot tips and clonal multiplication of Costus speciosus in long term culture. Plant Sci. Lett. 35, 67-71.
Punyarani, K., Sharma, G. J., 2010. Micropropagation of Costus speciosus (Koen.) Sm. using nodal segment culture. Not. Sci. Biol. 2(1), 58-62
Malabadi, R.B.,Mulgund, G.S. and Nataraja. K.2005.Effect of Triacontanol on the micropropagation of Costusspeciosus (Koen.) sm. using rhizome thin sections. In vitro cell. Dev.Biol-plant.41,129-132.
Robinson, P. J., Britto, J. S., Balakrishnan, V., 2009. Micropropagation of Costus speciosus (Koem. Ex Retz.) Sm., an Antidiabetic plant by using explants of pseudostems. Bot. Res. Intl. 2(3), 182-185.
S. S. Purohit 2005 Biotechnology Fundamentals and Applications