Micropropagation of Acacia tortilis hayne (umbrella thorn) through cotyledonary node culture

Multiple shoots were induced from cotyledonary node explants of in vitro grown seedlings ofAcacia tortilis Hayne on several treatments of cytokinins alone or in combinations with auxins incorporated in Murashige and Skoog's (MS) medium. Maximum average number of shoots per explant was 7–9 in medium with Kn (0.5 mg l⁻¹) or BAP (2.0, 2.5 and 3.0 mg l⁻¹) and 5–7 shoots per explant in combination of BAP (2.0 mg l⁻¹) with IBA (0.5 mg l⁻¹). The initial growth of adventitious shoots was slow as compared to axillary shoot and elongation was achieved by transferring the explants as such or after excising the axillary shoot to fresh medium in subsequennt passage. The medium containing Kn and IBA (0.5 mg l⁻¹ each) was found favourable for the development of complete plantlet as well as for rhizogenesis of isolated shoots.