Effect of IBA on root development and associated biochemical changes in single- and double-node stem-cuttings of spine gourd

Abstract

The present study was carried out to induce rooting in
single- and double-node cuttings of Momordica dioica
Roxb. variety Indira Kankoda-2 (RMDSG-3) under controlled
conditions and to investigate associated biochemical
changes during root development. The cuttings were treated
with six different concentrations of IBA (0, 1100, 1200, 1300,
1400, 1500 mg/l) at four soaking durations (5, 10, 15 and 20
second). Among five concentrations of IBA tested, 1500
mg/l IBA + 5 seconds soaking duration gave the highest
percentage of rooting, number of roots, and root length in
both single and double node stem cuttings. As a result, IBA
1500 mg/l was used further in this investigation for
biochemical studies. The adventitious rooting was obtained
in three distinct phases i.e., induction (0–12 days), initiation
(12–14 days) and expression (14–18 days). IAA-oxidase
activity of cuttings treated with IBA increased slightly as
compared to control, this activity was found to decrease
during induction and initiation phases and increase during
the expression phase. The peroxidase activity of cuttings
treated IBA-1500 mg/l increased up to initiation phase and
decreased during the expression phase. Polyphenoloxidase
enzyme activity/mg protein/min increased in both treated
(0.9-1.75) and control (0.5-0.8) cuttings during induction and
initiation phase but declined slowly during the expression
phase. Total phenolic content was measured in mg/gm fresh
weight, and it was found to be higher (6.55 mg/g fresh weight)
in IBA- 1500 mg/l treated cuttings, particularly in initiation
and expression phases, and it was also positively correlated
with peroxidase activity. Phenolic compounds may be used
as a rooting enhancer in spine gourd, and they can play a
key role in inducing adventitious rooting. IBA is foundefficient
in spine gourd rooting, and by utilizing this protocol
i.e., double node cuttings treated with 1500 ppm IBA for 5
seconds duration, spine gourd can be commercially
propagating.