Development of an efficient micropropagation system for Dioscorea bulbifera L. and phytochemical profile of regenerated plants.

BACKGROUND: The present study was designed to develop an improved in vitro regeneration system for Dioscorea bulbifera using mature nodal explants. Direct organogenesis from nodal segments was achieved by culturing the nodal explants on Murashige and Skoog medium supplemented with 3.5 mgl-1 6-benzylaminopurine (BAP). Shoot multiplication was widely affected by the kind and concentration of plant growth regulators, and the sub-culturing of in vitro regenerated shootlets on fresh medium. After incubation for 4 weeks at optimum BAP concentration, cultures were transferred to secondary medium with BAP (optimized concentration) supplemented with different auxins. RESULTS: On medium with 3.5 mgl-1 6-benzylaminopurine, maximum regeneration (87 ± 1.85%) with an average shoot number of 2.0 ± 0.08, and length of 3.5 ± 0.04 cm were observed after 4 weeks of incubation. Maximum number of shoots (3.9 ± 0.21) was observed with 3.5 mgl-1 BAP in combination with 0.75 mgl-1 indole-3-acetic acid. The best root formation was observed on ½ MS medium supplemented with 0.75 mgl-1 α-naphthalene acetic acid, with 4.7 ± 0.03 roots per shoot. The well-rooted plantlets were successfully acclimatized in with 100% survival rate. The plantlets grew well with normal growth, flowering and showed, by High performance thin layer chromatography, almost same number of phytoconstituents compared with the mother plant. CONCLUSIONS: This is the first study on comparative phytochemical analysis of wild growing and in vitro regenerated plants of D. bulbifera which validates the medicinal and nutritional properties of in vitro raised plants.