An efficient protocol for rapid clonal propagation from different explants of Aerides odorata Lour.- an endemic orchid of Manipur has been established. Leaf base explants showed significant response in ½ strength Murashige and Skoog medium supplemented with thidiazuron (TDZ) and 6-benzylaminopurine (BAP). Callus were initiated only from leaf base explants after 60 days of culture while other parts of leaves failed to response in all the treatments. Medium supplemented with 1.0 mg/L TDZ produced protocorm like bodies (PLBs) at the leaf base. Shoot tip explants of A. odorata showed different morphogenetic responses in different phytohormone treatments. Calli were initiated only in the medium containing α-naphthalene acetic acid (NAA). Highest calli frequency was observed in the medium containing 2 mg/L (NAA) (85.71±0.21) which indicates the importance of exogenous auxin in embryonic callus proliferation. Direct shoot regeneration on the other hand was observed in all the treatments. Highest number of shoot was obtained in higher concentration of NAA (2 mg/L) and BAP (4 mg/L) (4.80±0.18), showing combined effect of BAP and NAA, which may be due to the synergistic effect of cytokinin and auxin. Among the different rooting phytohormones, addition of NAA (0.5 mg/L) in ½ MS medium shows highest frequency of root induction. More than 95% in vitro plants survived during acclimatization under ex vitro conditions. This phytohormones and explants based micropropagation system can open up the route for in vitro clonal multiplication of this commercially important Aerides species.
Full Text:PDF
