Rapid plant regeneration from callus cultures of Plumbago zeylanica

Rapid plant regeneration was achieved in callus cultures derived from leaf and stem explants of Plumbago zeylanica Linn. on MS basal medium supplement ed with 4.44 mu M 6-BA, 1.42 mu M IAA and 3% (w/v) sucrose. The rate of sho ot bud regeneration was positively correlated with the concentration of gro wth regulators in the nutrient media. The leaf explants were more responsiv e (82.3%) than the stem explants on medium containing 1.42 mu M IAA in comb ination with 4.44 mu M BA. The rate of regeneration was found to maintain t he same level for 12 months without loss of vigour. Rooting of the differen tiated shoots was achieved in media having 0.57 mu M IAA with 2% (w/v) sucr ose within 10 days of culture. Regenerated plantlets were transferred to so il which grew normally with a survival rate of 90%. This protocol may help in the conservation of the species and selection of variants that may be in duced to widen the genetic base of the genus.