The role of plant growth regulators on direct and indirect plant regeneration from various organs of Leucaena leucocephala

Prolific differentiation of shoot buds of Leucaena leucocephala was induced from the different plant parts viz. cotyledon, hypocotyl and leaf. Adventitious shoot bud formation was recorded with prudent application of N6-2- (isopentenyl) adenosine and 15 % (v/v) coconut water. Coconut water alone was unable to produce any beneficial effect with regard to the shoot bud proliferation but the response was augmented with the increase in concentration of N6-2- (isopentenyl) adenosine. However supra-optimal level of N6-2- (isopentenyl) adenosine was inhibitory. Best response was recorded from the cotyledon explant at 2 mg·dm-3 N6-2- (isopentenyl) adenosine compared to the other two explants. Comparative assessment was undertaken following the same experimental protocol in liquid shake culture. The regenerated shoot buds were subcultured in plant growth regulator-free medium where leafy shoot emergence was recorded. Optimum regeneration of roots was observed in these shoots in presence of 1 mg dm-3 α-naphthalene acetic acid. Plantlets were finally hardened following standard procedures before transplantation to the field. In another experimental set up, the de-embryonated cotytedons regenerated shoot buds via callus formation. The regenerated shoots and plantlets obtained through callus mediated organogenesis could be used for rapid multiplication and also for the genetic improvement of individual clones of Leucaena leucocephala.