Vol. 3, Issue 2 (2018)
Effect of plant growth regulators on in vitro regeneration of Hemigraphis alternata (burm. f.) t. Anderson
Author(s): Krishna R Nair, Ashalatha S Nair
Abstract: An efficient shoot regeneration protocol for direct plant regeneration from nodal explants of Hemigraphis alternata- an important medicinal plant has been established. The aim of the present work is to figure out the auxin-cytokinin synergism on in vitro regeneration in this plant. In vitro shoot regeneration and proliferation was done on Murashige and Skoog Medium(MS) medium supplemented with different concentrations of cytokinins viz 6-Benzyl amio purine(BA), Kinetin(Kn) and Thidiazuron(TDZ) singly or in combination with auxins viz, Naphthalene acetic acid (NAA) or 2,4-Dichlorophenoxy acetic acid (2,4-D). Maximum number of shoots (10.39) with 4.72cm shoot length and highest regeneration frequency (87%) were obtained on MS medium supplemented with 3µM BA after 60 days of incubation. Among various combinations and concentrations of plant growth regulators tested optimum regeneration frequency (86%) of multiple shoot formation and highest number (11.67) of shoots per nodal explants was obtained in MS medium supplemented with a combination of BA (3µM) and NAA (0.75µM) after 60 days of incubation. The synergistic effects of Naphthalene acetic acid (NAA) (0.75µM) with BA (3µM) increased the regeneration frequency compared to other treatments. The optimum frequency (98%) of rhizogenesis was obtained on half strength MS medium having 2µM IBA after 30 days of incubation. Regenerated plantlets with well developed root system were successfully acclimatized in vermiculate and transplanted to soil with 97% survival rate.