Abstract

A method for in vitro regeneration of Maerua oblongifolia (Capparaceae) from nodal shoot explants is outlined. Percent shoot response with multiplication rate (21.1± 2.33) shoots per explant (30 mm length) was achieved when cultured on semisolid Murashige and Skoog (MS) medium containing 3% sucrose and supplemented with 2.0 mgl^-1 of (Benzylaminopurine) BAP + additives (25.0 mgl^-1adenine sulphate + 25.0 mgl^-1 citric acid + 50.0 mgl^-1 ascorbic acid). Further amplification of shoots was achieved when concentration of BAP was lowered (0.25 mgl ^-1) and Kinetin (0.25 mgl ^-1) along with 0.1 mgl ^-1 IAA was incorporated in the MS medium. A maximum of 58.1 ± 3.88 shoots of length 4-5 cm were obtained. The in vitro regenerated shoots rooted in vitro on half-strength MS medium containing 3.0 mgl^-1 of IBA. About 85% of shoot rooted (4.04 ± 0.96 roots per shoot) on this medium. Other auxins such as NOA also promoted rooting but, the response in terms of percentage of rooting (75%) and shoot number (2.9 ± 1.59 roots per shoot) was low as compared to IBA. In vitroregenerated shoots of length 4 to 5 cm having 1-2 nodes were excise individually and pulse treated with 200.0 mgl^-1 of IBA for 3.0 min for ex vitro rooting. After an initial acclimatization period of 2-3 months in a green house, about 80% plants were successfully hardened and were then transferred to earthen pots in nursery. Protocol developed is highly reproducible and economical as commercial agar and sugar cubes has been used. Multiplication rate is very high in vitro reported so far for this plant species. This standard protocol of mass propagation of M. oblongifolia eliminates the dependence on natural stands for seed production and will also serve for conservation of this threatened species.

Key words: Acclimatization, ex vitro rooting, in vitro, micropropagation, Maerua oblongifolia, soilrite