Effect of serial bud grafting and etiolation on rejuvenation and rooting cuttings of mature trees of Tectona grandis Linn. f.

摘要

An experiment was conducted to study the effect of serial bud grafting and etiolation on rooting stem cuttings. Auxiliary buds taken from two clones of mature teak trees and were grafted on root stocks of 2-year-old seedlings in 1998 and again serially grafted on 2-year-old root stocks in 1999. The grafts were maintained under complete darkness to induce etiolation. The etiolated shoot emerging from the grafted buds were made into mono-nodal, leafy cuttings, which were cultured under mist for rooting. Serial grafting and etiolation did not affect rooting, but treatment with IBA in combination with serial grafting and etiolation promoted root formation on the cuttings. All the control cuttings taken from lateral shoots after first or second grafting failed to root whereas, IBA-treated cuttings rooted very poorly after first grafting. However, rooting response in IBA-treated cuttings improved significantly after second grafting. Thus, serial grafting as well as etiolation caused only partial rejuvenation of mature clones. The two clones differed in their response to serial grafting and etiolation for induction of juvenility. Clone FG1 exhibited stronger rejuvenation, as indicated by more profuse rooting of the cuttings after second serial grafting. Clone FG11 exhibited comparatively weaker rejuvenation, which was indicated by less profuse rooting of the cuttings under similar conditions.