Potential of thidiazuron in improved micropropagation of it>bold>Picrorhiza kurroa/it>/bold>- an endangered medicinal herb of alpine Himalaya

摘要

The potential of thidiazuron (1-phenyl-3-(1, 2, 3-thiadiazol-5-yl) urea (TDZ) in the micropropagation of Picrorhiza kurroa, a western Himalayan herb was studied. The roots and rhizomes of this plant are rich in medicinally important glycosides i.e., picroside I, picroside II and kutkoside. Nodal segments (2.0-2.5cm) from plants were pretreated with 0, 0.25, 0.50, 0.75, 1.0M TDZ for 7, 15 and 30days. Maximum shoot multiplication was recorded after 60days, provided, the nodal segments pretreated with 0.5 M TDZ for 15 days were transferred to 0.8% agar gelled MS medium containing 3.0% sucrose. The shoots also showed profuse rooting having maximum length. When these plantlets were incubated at 15 degrees C for 10days and transferred to sand under polyhouse conditions, 100% survival was recorded after one month. In contrast, when the plantlets were not incubated at 15 degrees C, only 86% survival was recorded. While the stomata and chlorophyll content of the tissue culture-raised plantlets treated at 15 degrees C were comparable to that of plants growing in the field, the ones that were not treated at 15 degrees C showed lower number of stomata and chlorophyll content.