Improved Micropropagation Protocol of an Endangered Medicinal Plant-Picrorhiza Kurroa Royle ex Benth. Promptly Through Auxin Treatments

An efficient and rapid protocol for mass propagation of Picrorhiza kurroa Royle ex Benth - an endangered medicinal plant-in vitro without using cytokinin has been developed. The nodal explants were obtained from in vitro raised seedlings grown in moist cotton raised from chill treated seeds (4 degrees C) and in vivo matured plants in natural conditions respectively. Both types of genesis, direct and indirect, of shoot and root in this species using single type of hormones viz; auxins with MS basal medium is being reported for the first time. Among the various strengths of growth regulators tested best results were recorded when nodal explants from natural plants were cultured on MS basal media supplemented with 0.25 mg(-1) 2,4-D mgl(-1), 0.25 mgl(-1) BAP,0.2 mgl(-1) NAA and 0.6 mgl(-1) NAA for profuse callusing, shoot induction, indirect and direct rapid shoot proliferation respectively. Combination treatments of auxins were also testified but the results were not satisfactory as that of NAA alone. The rooting was also optimized using auxins alone or/and in combinations of two. The root induction per explants was maximum in the medium containing MS basal medium supplemented with 0.4 mgl(-1) NAA. The rooted plantlets were hardened in polycups containing sterile soil, sand and vermiculite in equal ratio and were successfully acclimatized and established in soil with 81.5 % survival rate.