Synergistic effects of BAP and kinetin media additives on regeneration of vetiver grass (Vetiveria zizanioides L. Nash)

Abstract

Regeneration efficiency was enhanced by adding auxin and cytokinin at different concentrations to the media.It was found that the two highest frequencies-90 and 85%-of callus induction occured when the buds were cultured in an MS medium supplemented with 2 mgL -1 α-naphthalene acetic acid (NAA) plus 1 mgL -1 N 6 -benzylaminopurine (BAP) (CIM2) and in the same medium supplemented with 2 mgL -1 NAA plus 1 mgL -1 kinetin (CIM5), respectively.When cultured further in a plant regeneration medium supplemented with 1 mgL -1 NAA and 2 mgL -1 BAP (PRM1), these calli regenerated with high efficiencies, 80% for calli grown in CIM2 and 85% for calli grown in CIM5.The low BAP concentration in CIM1 (2 mgL -1 NAA and 0.5 mgL -1 BAP) resulted in a low regeneration efficiency and fewer shoots per callus even though the PRM3 regeneration medium had a high concentration of cytokinins (2 mgL -1 BAP and 2 mgL -1 kinetin) .However, the calli cultured in CIM2 without kinetin but with a suitable level of BAP still regenerated with high efficiencies in PRM2 and PRM3 that contained 1 and 2 mgL -1 kinetin, respectively.Similarly, when calli cultured in CIM5 without BAP but with kinetin were regenerated in PRM1 with BAP alone, they also regenerated with a high regeneration efficiency.These results showed that culturing a specific tissue in a medium with suitable concentrations of NAA and BAP or kinetin resulted in a large number of multiple shoots, and BAP and kinetin worked synergistically to produce a high plant regeneration efficiency.