High efficiency plant regeneration from petiole explants of Carica papaya L. through organogenesis.

Callus cultures were obrained from petiole explants of Carica papaya on MS medium containing 0.5-10.5 μM α-naphthaleneacetic acid (NAA) in combination with 0.5-5 μM benzyladenine (BA). Hard-green calli were transferred to MS medium containing 100 mgl(-1) casein hydrolysate (CH) with specific BA-NAA formulation, where they developed adventitious buds within 2 weeks of culture. Maximum number of adventitious buds were obtained in 2 μM BA and 0.1 μM NAA. Shoot regeneration occurred from these adventitious buds by the end of the 4th week. Regenerated shoots were elongated in hormone-free medium and rooted in half-strength MS fortified with 3 UM NAA and 0.5 μM gibberellic acid (GA3). The regenerants were transferred to soil after acclimatization.