Springer Verlag, Proceedings of the National Academy of Sciences India Section B: Biological Sciences, 3(84), p. 837-846
DOI: 10.1007/s40011-014-0353-4
Full text: Download
An optimized method was devised for asymbiotic seed germination, seedling development and field establishment of Eulophia nuda Lindl., an endangered orchid with tremendous therapeutic potentialities. Seeds of different ages were germinated on half and full strength MS (Murashige and Skoog), KC (Knudson) and BM1 (Van Waes and Debergh) media. Amongst various supplements,15 % coconut water (CW) and 500 mg/L casein hydrolysate proved beneficial for seed germination. BM1 fortified with CW (BM1 + CW) showed the highest germination (80.5 ± 2.1 %) after 60 days of inoculation, which was further improved to 91.3 ± 1.9 % upon incorporation of 1 mg/L each of α-naphthaleneacetic acid (NAA) and 6-benzylaminopurine (BAP) and eventually 50.5 ± 2.1 % cultures developed into seedlings. BM1 + CW nourished with 2.5 mg/L BAP and 1.5 mg/L Kin (kinetin) proved best for multiple shoot induction from seedlings. Shoot numbers further increased with each successive transfer onto the same medium. Sixty shoots per shoot clump were achieved after four cycles of 30 days each. Microshoots were rooted (81.3 ± 2.4 %) on MS containing 2.0 mg/L indole-3-butyric acid (IBA) and 200 mg/L activated charcoal. Rooted plantlets were gradually acclimatized to greenhouse (70 % survival) and they exhibited normal morphology and growth characteristics. Flow-cytometry based DNA content analysis revealed that the ploidy levels were maintained in in-vitropropagated plants.