ESTABLISHMENT OF MULTIPLICATION PROTOCOL FOR INSULIN PLANT (COSTUS PICTUS D. DON) BY USING STEM NODE AS EXPLANTS

Costus pictus D. Don is a member of family Costaceae and commonly known as Insulin plant. A lot of research has been conducted to evaluate the anti-diabetic potential of this plant and revealed that a bioactive molecule tetracosonoate extract from Costus pictus leaves contain anti-diabetic activity. It is vulnerable species in India and due to indiscriminate collection now on the verge to extinction. It is found that the axillary buds of Costus pictus are dormant which limits it asexual propagation. Tissue culture may promise to preserve, protect and multiply this rare species for large scale multiplication. In the present study, a simple protocol for rapid mass propagation of Costus pictus was standardized using various concentrations of plant growth regulators like naphthalene acetic acid (NAA), 6-benzylaminopurine (BAP) and urea with Murashige and Skoog (MS) medium. The dormancy of axillary buds were successfully broken in stems cultured in MS medium with 1 ppm BAP, 0.5 ppm NAA (79.0%) and MS medium with 2 ppm BAP (66%). These sprouted in vitro axillary buds were used as secondary explants for shoot multiplication. The significantly highest numbers of shoots (6.67±0.65) per explants, shoot length (3.62±0.26 cm), roots number (9.71±0.52) per plantlet and root length (5.16±0.22 cm) was observed on MS medium supplemented with 1 ppm NAA, 4 ppm BAP and 10 ppm Urea. Primary and secondary hardening was done successfully. The micro-propagated plantlets do not show any visible morphological abnormalities.