Regeneration of plants from callus cultures of Origanum vulgare L.

Investigations were undertaken to achieve rapid multiplication and improvement of Origanum vulgare (a herbaceous, ornamental plant well known for its aromatic and medicinal value) through plant regeneration from callus. The explants (cotyledons, hypocotyl and root segments) excised from 15 d old aseptic seedlings were cultured on Gamborg's B₅ medium supplemented with 2,4-D, NAA and BAP individually and in various combinations (at concentrations of 0,10^–7,10^–6 and 10^–5 M). Best callus induction was noted on medium with 10^–7 M 2,4-D alone. The cotyledonary expiants proved to be the best source for compact and nodulated callus. The subcultured cotyledonary calli showed shoot induction when transferred onto media supplemented with BAP alone orin combination with 10^–7M or 10^–6MNAA. However, 10^–5M NAA completely suppressed the shoot inducing ability of BAP. In general, NAA promoted root induction from all explants used including cotyledonary callus. Best shoot induction was obtained on medium supplemented with 10^–6M BAP+10^–6MNAA. Both IBA and NAA at 10^–6 M proved to be equally effective in induction of roots from the cut ends of 15–20 mm long shoots (excised from callus) in half-strength B₅ liquid medium. Rooted shoots were successfully re-established in soil under controlled conditions.Abbreviations 2,4-D 2,4 dichlorophenoxyacetic acid - IBA indole-3-butyric acid - NAA -naphthaleneacetic acid - BAP 6-benzylaminopurine