Regeneration competence of Tainia latifolia (Lindl.) Benth ex Hook pseudobulb segments: an in vitro study.

摘要

Pseudobulb segments (~5 mm size) obtained from in vitro raised plantlets as well as greenhouse grown Tainia latifolia (Lindl.) Benth ex Hook were inoculated on different basal media, viz., MS, Mitra et al and Knudson 'C' with different levels of adjuncts. The explants from in vitro source out performed the in vivo sourced pseudobulb segments as for as initial morphogenetic response is concerned. Of the three basal media studied, MS medium in conjunction with 3% sucrose, 100 mg L-1 casein-hydrolysate (CH), 100 mg L-1 citric acid (as antioxidant) and 0.1% activated charcoal (AC) performed better. Within 7 wk of culture, the explants formed as many as 12 shoot buds on MS medium containing 3 micro M NAA+6 micro M BA, where about 78% explants responded positively. While 3-4 shoot buds developed after 10 wk of culture from the in vivo sourced explants on MS medium containing 3 micro M NAA+12 micro M BA and about 72% explants exhibited positive response. Incorporation of AC in the media proved to be promotory by reducing the browning of the medium and early initiation of the culture. The shoot buds from the initiation medium converted into rooted plantlets within 2-3 passages on MS medium containing 3% sucrose, 0.1% AC, 100 mg L-1 citric acid and 3 micro M NAA+9 micro M BA. The well rooted plantlets (~10 cm long with 2 or 3 roots) were hardened for 10-12 wk in culture vials containing 1/10th MS salt solution containing 2% sucrose, pieces of charcoal, coconut husk and chopped litter (1:1:1). The hardened plants were transferred to community potting mix and maintained in the poly-house for 7-8 wk before transferring to the wild. The transplants registered about 70% survival after two months of transfer.