Short
Communication
Post
Autoclaved Auxin Application in Rooting Medium Preparation by using Microwave
oven as heat source to liquefy the Semisolid medium – medium use to induce root
initiation in Eucalyptus Clone WK 013 Eh
Freddy Pangaribuan, SP - Plant
Tissue Culture Research
Tree Improvement - PT Wirakarya Sakti - Sinarmas Forestry
Jambi Region
Abstract
In horticulture, agriculture and forestry, vegetative
propagation is used extensively to produce elite clones from breeding program
and natural selection and rooting methods is one way to achieve this
objectives. NAA and IBA is the most
common auxin being used to perform the rooting purpose in vitro. Rooting in vitro use medium which is
supplemented with auxin to the ½ MS basal medium, FeEDTA, micro nutrient and
vitamin and sugar and sterilized using autoclaved. The rooting medium without auxin being autoclaved shows high
rooting rate. All treatment using from ½
MS NAA 0.6 ppm and IBA 0.6 ppm to 1/2MS NAA 2.4 and IBA 2.4 shows rooting rate
from 82% to 92%. This information gives
a possible solution to difficult to root clones using the medium with auxin
being autoclaved.
Introduction
F.W. Went (1935) use auxin for the first time
to develop his theory using Avena sp shoot tip to identify and quantify the
biological activity of growth hormone-auxin.
Auxin was identified as Indole-3-Acetic Acid (IAA) in 1934 and making
plant tissue culture possible (Arditti, J., Yam, T.W. 2009)
Practical application
of auxin for root initiation becomes possible when the discovery of a fact that
auxin also able to promote root initiation when added to the cut surfaces of
cutting (De Klerk et al, 1999). IBA is
the most widely used commercially, followed by NAA and IAA, Rhizopon produces
80% IBA and the rest is the other auxin.
IAA
continuous to be used in plant tissue culture inspite of evidence suggesting that it is unstable. The use of auxin, such as IBA, Naphthalene
acetic acid (NAA), and 2,4-dichlorophenoxy acetic acid, has increased because
they often appear to be more effective than IAA for
Induction of morphogenic responses. This enhanced effectiveness of auxin other
than IAA is presumed to be due to their stability. IBA is preferred for adventitious root
induction in woody species grown in
vitro, since it is more effective (Nissan and Sutter, 1990).
Clones Wk
013 Eh is a hybrid between E grandis x E pellita which has low rooting
percentage (less than 50%) using medium B2RE (Makro B2RE + NAA 1 + IBA
0.5). Medium B2RE are sterilized using
autoclaved for 20 minutes and used on daily basis for rooting activities.
An approach
have been conducted to improve the rooting percentage in rooted shoot of this
eucalyptus clone using this short communication reported i.e. ‘post autoclaved
hormone application’. Hormone NAA and
IBA are added to hormone free ½ MS medium in several concentration to see the
best concentration of hormone that will bring the highest rooting percentage.
Materials and Methods
Hormone free
½ MS medium were prepared using ½ MS Salt, micro MS, FeEDTA, Vit MS, Myo
inositol, sugar 20 g/l and agar. Medium
are adjusted to pH 5.8 using NaOH 1 N.
One day later the semisolid medium were prepared for the application of hormones. NAA and IBA stock (1000 ppm) are being
prepared by dissolving 0.1 g NAA or IBA using a few drops of NaOH I N with
stirring gently until dissolved
completely and add deionized water to reach 100 ml volume.
Treatment
for hormone is being done using sterilized pipette (autoclavable pipette and fin
tips) according to the treatment (Table 1.) by putting the hormone stock on the
semisolid media surfaces. The media were
later heated up using microwave oven for 1’30’’ (1 minute 30 second) to liquefy
the semisolid medium so the hormone can mixed through, and rest them to
solidify again. One day later the medium
was used for rooting micro shoot. Each
vessel contain 10 micro shoot, average shoot selected is 2-3 cm. All the rooted shoots were incubated in
growth room with temperature 20-26oC and light intensities 2800 lux using white
fluorescence lamp
Assessment
fro rooting rate was conducted 14 days later by calculating the number of shoot
that produces shoot with root and count the percentage. The data were processed using simple
statistic (Sigma Zone). The rooted shoot
was later transplanted to the nursery.
Results
Table 2. Rooting Rate
(%) of Post autoclave auxins treatment to initiate rooting shoot of Wk 013
Eh
No
|
Hormone
Composition
|
Replication
|
Average
(%)
|
|||||
NAA
|
NAA
|
1**
|
2
|
3
|
4
|
5
|
||
A
|
0.6
|
0.6
|
100
|
100
|
100
|
80
|
80
|
92
|
B
|
1.2
|
1.2
|
80
|
90
|
80
|
90
|
80
|
84
|
C
|
1.8
|
1.8
|
90
|
80
|
90
|
80
|
90
|
86
|
D
|
2.4
|
2.4
|
80
|
80
|
90
|
90
|
80
|
84
|
E
|
0
|
0.6
|
90
|
90
|
90
|
80
|
90
|
88
|
F
|
0
|
1.2
|
50
|
100
|
80
|
80
|
80
|
78
|
G
|
0
|
2.4
|
100
|
100
|
70
|
70
|
80
|
84
|
H
|
2.4
|
0
|
80
|
60
|
50
|
60
|
50
|
60
|
I
|
0
|
3
|
80
|
80
|
80
|
70
|
60
|
74
|
No hay comentarios:
Publicar un comentario en la entrada