Journal of Developmental Biology and Tissue Engineering Vol. 3(8), pp. 92-98, August 2011 Available online http://www.academicjournals.org/jdbte ISSN 2141-2251 ©2011 Academic Journals Full Length Research Paper Micropropagation of Maerua oblongifolia: A rare ornamental from semi arid regions of Rajasthan, India Mahender Singh Rathore* and Narpat Singh Shekhawat Biotechnology Unit, Department of Botany, Jai Narain Vyas University, Jodhpur, Rajasthan-342033 India. Accepted 15 July, 2011 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 -1 adenine 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 vitro regenerated 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. INTRODUCTION Maerua oblongifolia (Forsk) A. Rich in Guill and Perr. (Capparaceae) is locally known as Orapa (Bhandari, 1990). It is rare liana of the Thar Desert, and is a large, scabrous, unarmed, woody climbing shrub with pale- brown smooth bark. This plant bears greenish-white flowers, in corymbs on short lateral or terminal shoots. *Corresponding author. E-mail: mahendersr@gmail.com. Tel: +91 98291 33229. Abbreviations: BAP, Benzylaminopurine; IAA, indole-3- acetic acid; IBA, indole-3-butyric acid; Kn, kinetin; MS, Murashige and Skoog (1962) medium; NOA, naphthoxyacetic acid; PGR, plant growth regulator; RH, relative humidity; SFP, spectral flux photon. Fruits are pale-brown, 8 to 12 cm long, constricted between the seeds, forming an elongated, twisted and knotted berry; each knot is one-seeded. This plant exhibits wide variation in fruit size and morphology (Rathore et al., 2005). M. oblongifolia is a threatened plant in the area. Plant is woody climber and climbs over Prosopis cineraria, Maytenus emarginata, Tecomella undulata, Salvadora spp. and resembles Cocculus species. Plants produce aromatic flowers during summers. The ripe fruits are sugar rich, sweet with high calorific value and are rarely seen as these are eaten by squirrels and birds. M. oblongifolia due to its attractive aromatic flowers can be developed as garden and ornamental plant. M. oblongifolia is highly drought and high temperature resistant therefore it can be a potential target for gene prospecting. Plant provides shelter and