Effects of Commercial Plant Hormones on the Survival, Rooting and Growth of Stem Cuttings of an Herbal Tea Plant, Aidia racemosa

Abstract

Objective: The effects of three commercial plant hormones (Seradix containing 0.1% indolebutyric acid or IBA, Clonex containing 0.3% IBA and 'A fruit plus' containing cytokinins, gibberellins and auxins) on growth of Aidia racemosa (Cav.) Tirveng stem cuttings were investigated. Methodology: The cuttings treated with hormones and distilled water (control) were planted in soil and perlite media. The survival and rooting percentages, number and length of new roots per cutting, number and surface area of new leaves per cutting and the relative growth rates were assessed every 4 weeks for 16 weeks. Results: Clonex-treated stem cuttings showed slightly higher survival (75% at week 4 and 35% at week 16) and rooting (35% at week 16) percentages than other treatments. There were no significant effects of the hormone treatments on the various growth parameters investigated, however, it seems that stem cuttings treated with seradix and 'A fruit plus' produced higher number of new leaves (0.35 and 0.30, respectively) and clonex-treated stem cuttings produced larger leaves (0.72±0.66 cm²) than the other hormone treatments. Conclusion: This study suggests that clonex is the most suitable commercial hormones for the vegetative propagation of A. racemosa but more studies need to be conducted to provide an alternative but efficient way to produce planting materials of A. racemosa for the mass production of herbal tea.

Full text

OPEN ACCESS Research Journal of Medicinal Plants
ISSN 1819-3455
DOI: 10.3923/rjmp.2016.414.419
Short Communication
Effects of Commercial Plant Hormones on the Survival,
Rooting and Growth of Stem Cuttings of an Herbal Tea Plant,
Aidia racemosa
N.D.Z. Awang Kamis, H. Taha and F. Metali
Environmental and Life Sciences Programme, Faculty of Science, Universiti Brunei Darussalam, Jalan Tungku Link, BE1410,
Brunei Darussalam
Abstract
Objective: The ef fects of thre e commerci al plant ho rmones (Se radi x cont ainin g 0.1 % indo lebutyric acid or IBA, Clone x containing
0.3% IBA and A fruit plus containing cytokinins, gibberellins and auxins) on growth of
Aidia racemosa
(Cav.) Tirveng stem cuttings were
investigated. Methodology: The cuttings treated with hormones and distilled water (control) were planted in soil and perlite media. The
survival and rooting percentages, number and length of new roots per cutting, number and surface area of new leaves per cutting and
the relative growth rates were assessed every 4 weeks for 16 weeks. Results: Clonex-treated stem cuttings showed slightly higher survival
(75% at week 4 and 35% at week 16) and rooting (35% at week 16) percentages than other treatments. There were no significant effects
of the hormone treatments on the various growth parameters investigated, however, it seems that stem cuttings treated with seradix
and A fruit plus produced higher number of new l eaves (0.3 5 and 0.30, respec tively) and c lonex-t reated stem c uttings prod uced
larger leaves (0.72±0.66 cm2) than the other hormone treatments. Conclusion: This study suggests that clonex is the most suitable
commercial hormones for the vegetative propagation of
A. racemosa
but more studies need to be conducted to provide an alternative
but efficient way to produce planting materials of
A. racemosa
for the mass production of herbal tea.
Key words:
Aidia racemosa
, plant hormone, stem cuttings, relative growth rate, vegetative propagation
Received: July 21, 2016 Accepted: August 17, 2016 Published: September 15, 2016
Citation: N.D.Z. Awang Kamis, H. Taha and F. Metali, 2016. Effects of commercial plant hormones on the survival, rooting and growth of stem cuttings of
an herbal tea plant,
Aidia racemosa
. Res. J. Med. Plants, 10: 414-419.
Corresponding Author: F. Metali, Environmental and Life Sciences Programme, Faculty of Science, Universiti Brunei Darussalam, Jalan Tungku Link,
BE1410, Brunei Darussalam Tel: +6732463001
Copyright: © 2016 N.D.Z. Awang Kamis
et al
. This is an open access article distributed under the terms of the creative commons attribution License, which
permits unrestricted use, distribution and reproduction in any medium, provided the original author and source are credited.
Competing Interest: The authors have declared that no competing interest exists.
Data Availability: All relevant data are within the paper and its supporting information files.

Res. J. Med. Plants, 10 (6-7): 414-419, 2016
INTRODUCTION
Aidia racemosa
(Cav.) Tirveng (Rubiaceae), which is an
evergreen shrub native to Asian regions, possesses leaves that
contain medicinal properties and are beneficial to human
health1. The decoction of boiled leaves is consumed as a
remedy for gastric pain and to strengthen the back muscle
especially after heavy physical work. Other species in the
family Rubiaceae, such as
Hedyotis auricularia
,
Mussaenda
philippinensis
and
Oldenladia corymbosa
, were found to
reduce hypertension, cure ulcer, fever and diarrhea and
maintain stamina2. However, no studies have been made on
A. racemosa
yet. Closely related species, such as
A. de nsif lora
has been found to contain alkaloids in its leaves and seeds and
A. tomentosa
has been shown to contain saponin in its fruits1.
In Brunei Darussalam, the local villagers have been
harvesting the leaves of
A. racemosa
for the commercial
production of herbal tea. In order to expand the market,
supply and production issues are the primary constraints as
more plants are needed to keep up with the increasing local
demand. Since growing
A. ra cemosa
plants from seeds takes
a long time (germination may take 1-2 months)3, vegetative
propagation by stem cuttings is investigated. There have
been no previous studies on the vegetative propagation
of
A. racemosa
, so this study aims to examine the types of
commercial hormones that could be used to effectively mass
propagate as well as increase survival and rooting percentages
and relative growth rates of
A. racemosa,
which could
potentially help to regulate market supply in the long run and
conserve the plants in the wild.
MATERIALS AND METHODS
Sampling: Stem cuttings of
Aidia racemosa
were collected in
Kampong Kiudang, Tutong, Brunei Darussalam (N 04 4249.8,
E 114 4635.8, elevation 69 m). The stem cuttings (14 cm in
length) were obtained by cutting the woody shoot tips using
sharp secateurs that had been sterilized with 70% ethanol. The
stem cuttings were placed in a plastic bag, which was
regularly supplied with distilled water to prevent them from
getting dehydrated.
Preparation of stem cuttings: Stem cuttings were brought
back to the biology laboratory for subsequent treatments with
hormones. A total of 20 stem cuttings were used for every
hormone treatment including the control treatment, which is
using distilled water. Strict hygiene practices were carried out
to eliminate the possibility of plant death due to microbial
contamination. Any fruits, flowers or flower buds that were
found on the stem cuttings were removed and the leaves
were cut to about two third of their original size in order to
encourage root and shoot growth. Initial measurements of the
stem cuttings include the shoot length (cm), diameter of
stem (cm) and number of leaves.
The commercial plant hormones used in this study
were seradix (0.1% indolebutyric acid or IBA), clonex (0.3%
IBA) and A fruit plus (a biostimulant containing unknown
concentrations of cytokinins, gibberellins and auxins). The
plant hormones were obtained from the local markets, so that
they could be used by the villagers for the intended purpose.
The hormones were applied to the stem cuttings using the
basal quick-dip method following Abidin and Metali4, whereby
the cut end of stem cuttings were dipped 1-2 cm in the
hormone powder or solution for 5-10 sec.
Preparation of growth media and growth conditions: The
stem cuttings treated with the commercial hormones or
distilled water (control) were immediately planted onto a
growth medium containing a 1:1 mixture of perlite and soil,
which was pre-autoclaved to kill any contaminating microbes.
A total of 80 g of the autoclaved soil mixture wa s poured
into each of the well-drained, square-based plastic pot
(16 cm2×7.5 cm). A volume of 50 mL of distilled water was
subsequently poured onto each pot to avoid the cut surfaces
of stem cuttings to come into contact with any dry soil
pockets. All the plants were kept in the greenhouse that was
installed with an automatic misting system that operated
every 5 min to spray water onto the plants. The stem cuttings
were grown at 27-31EC, relative humidity of 80-90% and
light at 300 μmoL mG2 secG1 (measured with an Apogee
QuantumMQ-200 PAR Meter, Apogee Instruments, UK). The
pots were randomly arranged on the benches and were
moved to new random positions every week. A plastic
transparent sheet was used to cover the pots of plants on the
bench in order to retain high atmospheric humidity, promote
rooting and reduce transpirational loss.
Assessment of cuttings: The study was conducted for a total
of 16 weeks and the measurements of the stem cuttings
conducted every 4 weeks following Aminah
et al.
5, included
survival and rooting percentages (%), number and area of
new leaves (cm2) per cutting, number and length of roots (cm)
per cutting and Relative Growth Rate (RGR) based stem length
and stem diameter (cm cmG1 weekG1). The Relative Growth
Rate (RGR) based on either stem length or stem diameter per
stem cutting was calculated according to Hunt6 as follows:
e2 e1
21
log W log W
RGR (t t )



415

Res. J. Med. Plants, 10 (6-7): 414-419, 2016
Seradix
Clonex
A fruit plus
Control
(a)
100
80
60
40
20
0
0 4 8 12 16
(b)
100
80
60
40
20
0
0481216
where, W1 and W
2 represent the initial and final values,
respectively, for either the stem length or stem diameter and
t2 was considered either week 4, 8, 12 and 16, while t1 as the
initial week. Any plants with their leaves and/or stems that
turned brown were considered dead and their measurements
were stopped.
Statistical analysis: Prior to statistical analysis, assumptions
of normality and equal variances of data were checked and
found to be violated. Therefore, Kruskal-Wallis non-parametric
tests were conducted to compare each of the parameters
measured between the different hormone treatments
and control. Statistical analysis were conducted using
R version 3.2.37.
RESULTS
Survival and rooting percentages: The stem cuttings
treated with clonex, containing 0.3% IBA as its active
ingredient, had the highest survival percentage at
week 4 (75%) and week 16 (35%) (Fig. 1a). The stem
cuttings treated with seradix, A fruit plus or distilled water
(control) had low survival percentages, ranging from
10-20% at week 16. The seradix-treated stem cuttings had
the lowest survival percentages at week 12 (15%) and
16 (10%).
None of the stem cuttings rooted at week 4 (Fig. 1b).
The stem cuttings treated with clonex had the highest
rooting percentages (30-35%) compared to other treatments
including distilled water at the remaining weeks (week 8 -16).
The seradix-treated stem cuttings had the lowest rooting
percentages (5-10%) compared to other treatments including
distilled water (control). Rooting percentages for stem cuttings
treated with A fruit plus and seradix were found to be lower
than the ones treated with distilled water.
Effects of commercial hormones on root and leaf
development: There were no significant differences between
the different hormones used and distilled water for each of the
evaluated parameters at week 4, 8, 12 and 16. Only data at
week 16 were shown in Fig. 2.
At week 16, stem cuttings treated with distilled water
(control) as well as the commercial plant hormones showed a
consistently low mean number of roots produced per cutting
ranging from 1.7-1.8 (Fig. 2). The control treatment resulted in
higher mean length of roots (29.1±12.5 mm) produced per
cutting than the rest of the treatments. Stem cuttings
treated with seradix and A fruit plus appeared to produce
high number of new leaves produced (0.35 and
0.30, respectively) per cutting but no new leaves were
produced for stem cuttings treated with distilled water.
However, despite the low number of new leaves produced,
clonex-treated stem cuttings appeared to produce larger
leaves (0.72±0.66 cm2) per cutting when compared to the rest
of the hormone treatments. The RGR values based on stem
length and stem diameter were relatively low for all of the
treatments but the greatest mean RGRstem d iameter was
found in stem cuttings treated with A fruit plus
(0.003±0.002 cm cmG1 weekG1).
Fig. 1(a-b): (a) Survival and (b) Rooting percentages of
Aidia racemosa
stem cuttings (initial number of stem cuttings = 20)
treated with commercial hormones or distilled water (control) over 16 weeks
416

Res. J. Med. Plants, 10 (6-7): 414-419, 2016
Control
4
3
2
1
0
Root number
Seradix Clonex A fruit plus
Treatments
(a)
Control
50
40
30
20
10
0
Root length (mm)
Seradix Clonex A fruit plus
Treatment
(b)
Control
0.010
0.008
0.006
0.004
0.002
0.0 Seradix Clonex A fruit plus
Treatments
(e)
RGR stem length (cm cm week )
GG
11
Control
No. of new leaves
Seradix Clonex A fruit plus
Treatments
(c)
0.8
0.6
0.4
0.2
0.0 Control
Area of new leaves (cm )
2
Seradix Clonex A fruit plus
Treatments
(d)
2.0
1.5
1.0
0.5
0.0
Control
0.010
0.008
0.006
0.002
0.0
RGR stem diameter (cm cm week )
GG
11
Seradix Clonex A fruit plus
Treatments
(f)
s
Fig. 2(a-f): (a) Root number per cutting, (b) Root length (cm) per cutting, (c) No. of new leaves per cutting, (d) Area of new leaves
(cm2) per cutting, (e) RGR based on stem length and (f) RGR based on diameter of
Aidia racemosa
stem cuttings
subjected to different treatments (distilled water, seradix, clonex and A fruit plus) at week 16. Values are
Means±Standard Error (SE)
DISCUSSION
Vegetative propagation method provides the facilitation
of rapid multiplication of plant s to meet the in creasing
demand for planting materials of
Aidia racemosa
which is the
main focus of this study. It is hoped that the use of vegetative
propagation would minimize any need to collect the wild
plants from the forest and this would help in protecting our
417

Res. J. Med. Plants, 10 (6-7): 414-419, 2016
pristine forest. This study revealed that stem cuttings treated
with clonex had the highest survival and rooting percentages
than the rest of the treatments. Mehrabani
et al.
8 reported
that the immediate formation and the subsequent growth of
roots are the most influential factors affecting the survival of
cuttings. The successful rooting of stem cuttings could be
influenced by many other factors, such as the rooting
medium, the environmental conditions as well as the
physiological status of the stock plant itself9. Although the
survival percentage for stem cutting treated with clonex is
enough to propagate
A. racemosa
, the overall low survival and
rooting percentages for stem cuttings suggest that the
commercial hormones used in this study are probably not
completely suitable for the propagation of this species using
stem cuttings.
Although there was lack of studies on vegetative
propagation using clonex, the active ingredient IBA had
commonly been used in the propagation of several species of
plants from stem cuttings. However, the results varied
depending on the concentration of IBA used. A study
conducted by Maile and Nieuwenhuis10 showed that the
application of 0.8% IBA did not effectively influence the
adventitious root formation on
Eucalyptus nitens
stem
cuttings. However, a study by Kipkemoi
et al
.11 showed that
stem cuttings of
Strychnos heningsii
treated with IBA and
seradix 2 powder produced more and longer roots and had
higher rooting percentage than those treated with NAA and
IAA. The study also showed with hormone treatments
(IBA, NAA and IAA), the mean number of roots as well as
rooting percentage of cuttings increased with increasing
concentrations (up to 0.015%). The Seradix hormone used in
this study contained 0.1% IBA so this could explain the low
survival and rooting percentages. The commercial hormone
 A f ru i t p l us  co n ta i ns b io s ti m ul a nt a nd c yt o ki n in s , g i bb e re l li ns
and auxins. Cytokinins and gibberellins are not commonly
used in studies involving vegetative propagation and
generally known to have little or no effects on rooting. This
could explain the failure of stem cuttings to produce more
roots when A fruit plus was used.
The present study reported no significant effects of the
hormone treatments and distilled water for each of the
parameter investigated, but seradix and A fruit plus seem to
increase leaf production and clonex to produce larger leaves.
This current work also suggested that more studies on
different growing media need to be conducted as this factor
may improve the growth rates, number and length of roots
and number and surface area of leaves. For example, Saradha
and Samydurai12 claimed that coconut fiber and vermiculite
are preferably used as growing media to improve the aeration
and moisture capacity. Other methods of propagation, such
as
in vitro
propagation, could be explored for the mass
propagation of
A. racemosa
. Khalil
et al.
13 successfully
propagated
Stevia rebaudiama
using micropropagation
techniques with 85% success rate when compared to
propagation using stem cuttings (60%).
CONCLUSION
From the present findings, treating
A. racemosa
stem
cuttings with clonex (0.3% IBA) resulted in high survival and
rooting percentages, however, the use of commercial
hormones as well as distilled water did not produce a
significant difference in terms of the growth parameters under
investigation. However, it appeared that stem cuttings treated
with seradix and A fruit plus produced high number of new
leaves (0.35 and 0.30, respectively) and clonex-treated stem
cuttings produced larger leaves (0.72±0.66 cm2) than the
other hormone treatments. More research needs to be done
to provide an alternative but effective approach in the mass
production of
A. racemosa
plants for the herbal tea market.
ACKNOWLEDGMENTS
This study was funded by the research grant provided by
Universiti Brunei Darussalam. We thank the Kg. Kiudang
Mungkom Village Consultative Council in Tutong, Brunei
Darussalam for their kind assistance in making this study
possible.
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