In vitro organogenesis and plantlet regeneration of ( Carica

An efficient protocol was developed for micro-propagation of Indian papaya (Carica papaya L.) var. Co7. Shoot bud induction occurred on culturing epicotyl segments in MS (Murashige and Skoog, 1962) medium, followed by transfer onto shoot multiplication, elongation and rooting media. Adventitious buds were induced on MS medium supplemented with varying concentration of thidiazuron (TDZ: 0.5-10 μM). The highest shoot regeneration frequency and maximum number of shoots per explant was occured on MS medium amended with 2.5 μM TDZ. The explants with initiated shoot buds produced multiple shoots in MS medium supplemented with 5.0 μM 6-benzylaminopurine (BAP) and 0.05 μM naphthaleneacetic acid (NAA). Maximum shoot elongation was observed at 1.5 μM gibberlic acid (GA3). Upto 60.25% of the regenerated (elongated) shoots were rooted on MS medium containing 2.5 μM indole-3butyric acid (IBA) within 3 weeks after subculturing. The in vitro-raised plantlets were successfully hardened first under culture room conditions, then in greenhouse with 72% survival rate. The identified regeneration system could be efficiently used in various in vitro manipulation studies in papaya.