In vitro multiplication of Wthnia somnifera auxiliary buds for mass propagation

Abstract

Wthnia somnifera of family Solanaceae commonly known as Amukkara or Ashwaganda is animportant medicinal perennial herb with long tapering roots. The roots arc widely used in ayurvedicmedicine and prescribed for hiccup, female disorders, cough and rheumatism. Wild and cultivatedforms are available and cultivated plants differ in morphological and therapeutical action from wildones. The annual requirement 01'42347 kg is imported from India spending Rs. 2, 840,449 (lUCN ,20(5). Development ofa method for in vitro mass production of this valuable species would substantiallyreduce the import cost and generate employment opportunities. This study was conducted to developan ill vitro protocol for mass production of W somnifera

In vitro grown seedlings ofW. somniferaweie used to excise single nodal cuttings and cultured onMS (Murashige & Skoog, 1962) medium. The effect ofNAA (0, 0.1,0.2 mg/I) in combination withBAP (0.5., 1.0, 1.5 mg/l) on shoot proliferation was tested in solid and liquid MS media containing twolevels of sucrose (3% and 4%). Proliferation (number of plant lets produced) was observed at weeklyintervals.

Highest shoot proliferation rate (I: 20) was observed in solid MS medium containing 3% sucrose and1.5mg/1 BAP after two months. In solid MS medium with 4% sucrose and 1.0 rng/l BAP 1: 10 shootprol iferation rate was observed after two months. During the same time period I: IS shoot prol iferationrate was observed in solid MS medium with 3% sucrose, 0.5 mg/l BAP and 0.2 mg/l NAA, where I:12 proliferation rate was observed when BAP concentration increased up to 1.0 mg/l. Solid MS mediaboth with 3% and 4% sucrose levels and 0.5 mg/l BAP showed some proliferated shoots while othersolid cultures were not proliferated. However cultures containing NAA in addition to BAP enhancerooting of proliferated shoots before transferring the separated shoots to rooting media. The explantsin liquid MS medium with 4% sucrose and 1.0 mg/I BAP, proliferation initiated in one week andgavc 1:40 shoot multiplication rate after two months. Rest of the liquid cultures with different BAPand NAA combinations were not proliferated within the same time duration.

Finally it can be concluded that highest shoot proliferation of W sonmifera through single nodalcuttings can be obtained on liquid MS medium with 4% sucrose and 1.0 mg/l BAP.