0

MINISTRY OF EDUCATION MINISTRY OF AGRICULTURE AND
AND TRAINING

RURAL DEVELOPMENT

VIETNAM ACADEMY OF AGRICULTURAL SCIENCES

NGUYEN THI LAI

STUDY ON BIOLOGICAL CHARACTERISTICS AND
PROPAGATION TECHNOLOGY USED FOR
PRESEVATION OF (Dendrobium loddigesii Rolfe,
Dendrobium aphyllum (Roxb.) Fisher) VIETNAM
ORCHIDS
Speciality:

Crop science

Code:

9 62 01 10

SUMMARY OF DOCTORIAT THESIS

Scientific supervisers:
1. Prof. Dr. Vu Manh Hai
2. Dr. Pham Huong Son

HA NOI - 2019

with high value of medicine and commerce. As mentioned in the documents
of traditional Chinese medicine, D. loddigesii Rolfe can be used as a blood
anti-freezer and in protection of some cancer diseaseas orcured in human
organs like stomatch, lung, (Tsai et al., 2010); prospate, oesophagus…and in
treatment of diabetes (Veronika Cakova et al., 2017); skin color whitening
(Ho Kyung Jung et al., 2015). D.aphyllum (Roxb.) Fisher. takes an important
role in treatment of some diseases like cough, throatsore, flame burning, food
poisoning etc….(Vietnam red book, 2007).
As a matter of fact, D. loddigesii and D.aphyllum orchids have been
seriously exploited in recent years for ornamental decoration and medicine as
well resulting in strongly germplasm erosion. In addition, the germination
ability of these orchids in natural condition is very low whereas its
distribution is quite limited, its availability, is therefore, met a lot of
difficultities in terms of areas existed and individual quantity as well.
Because of that, the study on multiplication technology targeted firstly for
preservation and development of these orchid species takes an very
important role in which in vitro propagation and synthetic seed create
techniques aimed to prolong the seed conservation duration should be paid
great attention to. This direction is regarded as an effective way not only for
D. loddigesii and D.aphyllum orchids but also for other rarely precious ones
as well. With the aim of diversification of Vietnam valuable medicine
resources, partly improvement of vital environment and orchid producers
living standard, a sicientific thesis entitled “Study on biological
characteristics and propagation technology used for preservation
(Dendrobium loddigesii Rolfe, Dendrobium aphyllum (Roxb.) Fisher)
Vietnam orchids” was proposed for implementation.
2. Objectives of the thesis
To evaluate the fundamental biological characteristics of D. loddigesii
and D. aphyllum orchid species and in vitro propagation techniques aimed to
its reservation for development of highly valuable medicinal and ornamental

-Thesis is a synthesized scientic study on morphologycal characteristics,
micro strucrure and bio chemistrical ingradients of valuable medicinal and
ornamental orchid precies named D. loddigesii and D. aphyllum.
- In vitro propagation technical procedures of precious D. loddigesii and
D. aphyllum orchids have been established that can be easily and effectively
applied in the condition of Vietnam because of material availablity.
- Techinical procedures of synthetic seed production and in vitro post
preserved synthetic seed multiplication of these orchid species have
prolonged the conservation duration with low cost, high percentage of its
germination (68% to 70%) without variety character change.
- Fundamental techniques used in in vitro and in nursery propagation of
D. loddigesii and D. aphyllum orchids have been sucessfuly dertermined,
from which completely technological procedure used for large scale
propagation shoulde be established.

5. Structure of the thesis
The thesis consists of 130 pages uncounted the references and appendix
36 tables, 36 pictures and figures, 169 scientific works published in Vietnam
and outsides cited were involved in the document. Thesis content was


3

devided into diiferent parts : introduction (3 pages); Chapter 1: Over all
documentation concerned and scientific basic of the thesis (34 pages);
Chapter 2: Material, content and methods of the study (14 pages); Chapter 3:
Results and discussion (72 pages); Concusions and proposals (2 pages);
References (16 pages) and appendix (25 pages).
CHAPTER 1. OVER ALL DOCUMENTATION
1.1. Origin and distribution of D. loddigesii and D. aphyllum orchid

D. aphyllum
Subordinated living with thinh
and bended stems of
100 cm long. (Tran
1998).

about
Hop,

Long handled machete leaves
of 6 - 8 cm long, 1,5 - 2 cm
1 - 2 cm wide and easily droped
wide (Vietnam red
book
(Tran Hop, 1998).
2007).
Clusters of 1-2 flowers of dark
Clusters of 1 – 3 flowers of
pink color with dark pots
light purple color generated
located in leaf sides Petals are
from leafless stems.
Petals
round with smooth hairs in its
with three veins are
light
edges and
yellow colored yellow
color.
Flowering

and exportation (39.7%), followed by Thailand (28.4%); Taiwan (10%),
Singapore (10%) and New Zealand (6%). Main import countries are Japan
(30%), United Kingdom (12%), Italy (10%), France (7%) and United States
of American (6%). Of cut flower orchids exchanged in the world markets,
Dendrobium (85%) and Phalaenopsis, Cymbidium ( 15%) are considered to
be principal ones (Cheamuangphan et al, 2013; De et al., 2014). In
Netherland, the production of pot Dendrobium has increased significantly a
quantity of about 40 to 50 mil of orchid individuals produced annually was
reported (De et al., 2014).
In Vietnam, the area under orchid cultivation has been limited
accounting approximately 10% of total flower cultivated area. Present
production of orchid flowers in Vietnam is implemented in two orientations:
The industrial production is applied for newly released orchid varieties or
introduced ones whereas utilization and exploitation of indeginous orchids is
prioritized for available cultivars mainly taken from the forests.
It is also obvious that orchid production in Vietnam does not meet the
demand of domestic consumtion, only 30 - 40% orchid quantity required is
produced in country and the rest has to be imported from outsides.
1.5. Study on biology and multiplication situation of Dendrobium in


5

Vietnam and over the world
1.5.1 Study on biology of Dendrobium
Study on leaf and pseudobulbs morphological and physiological
characteristics of 4 orchid species D. chrysotoxum, D. officinale D.
crystallinum and D. crystallinum in the relation with maintaining water
balance was reported by Shi-Jian Yang et al., (2016) whereas Metusala et al.,
(2017) focused on micro morphological structure of stem and leaf of D.

anatomy and transpiration characteristics of micropropagated D. anosmum


6

Lindl. during ex vitro acclimatization process. Nguyen Thi My Duyen et al.,
(2012) studied on morphological based classification of Dendrobium and
from which three new species namely D. pulchellum, D. gatton Sunray, D.
moschatum was nominated. These species were closely relative with genetic
coefficiences of 96.5% and 95.0% respectively. In a study done by Tran Duy
Duong (2015), the morphological index was combined with molecular
markers in polymorphic evaluation of 32 Vietnam indigenous Dendrobium
accessions including higly valued medicinal species such as D. jenkinsii, D.
lindleyi, D. aphyllum…
It seems, however, no study on bio-chemical composition of
Dendrobium orchid has been reported in Vietnam up to now.
1.5.2 Study on propagation of Dendrobium over the world
1.5.2.1 Study on in vitro propagation
Various scientific works on in vitro propagation have been done over the
world. Dake Zhao et al., (2013) had a research into multiplication and in
tube flower formation of D. wangliangii. Xin Qian et al., (2014)
implemented a study on in vitro flowering and fruiting in culture of D.
officinale. Calluses were induced from shoot-tip explants of D. officinale on
MS medium with 0.2 mg/l BA and 0.05 mg/l αNAA. Multiple shoots had
been regenerated after protocorm like bodies were transferred onto the same
basal medium with 1.0 mg/l αNAA. The plantlets, 2 - 4 cm high, maintained
in vitro were induced to flower, and the highest rates of inflorescence
(83.2%) and normal flowers (73.6%) were produced on the MS medium with
15% coconut water and 0.1 mg/l TDZ within 9 weeks.
Mohammad Musharof Hossain et al., (2013) studied on multiplication

Lindley (Nguyen Van Viet, 2017), D. transparens (La Viet Hong et al.,
2017), D. officinale (Le Thi Diem and Vo Thi Bach Mai, 2017),…
1.5.2.2 Study on synthetic seed formation of orchids
Up to now, protocorm and PLBs have been mainly used in the studies
on synthetic seed formation of orchids (Bunnag et al., 2010; Zhang et al.,
2011; Mohanty et al., 2013; Bustam Suryanti et al., 2013; Sukhumpinij et
al., 2015; Nhut et al., 2005; 2007; Tran Thi Ngoc Lan, 2013).
1.5.2.3 Study on the growth and development of orchid plants generated
from preserved or non preserved synthetic seeds.
Using RAPD technique for polymorphic evaluation of Cineraria
maritana, Srivastava et al., (2009) reported that there was no genetic
difference between plantlets generated from non preserved seeds and 6
months preserved ones. The same result was also reported by Mishra et al.,
(2011) in Picrorhiza kurrooa (3 months preserved seeds) and Mohanty et al.,
(2013) in D. densiflorum (60 days preserved seeds).
1.5.2.4 Study on cultivation of Dendrobium
Mohammad Musharof Hossain et al., (2013) stated that mixture of brick
pieces, charcoal pieces, coco peat and vermiculite at 1 : 1 : 0.5 : 0.5 ratio
was considered suitable for plantlet cultivation of D. aphyllum while Winarto et
al., (2015) recommended Cycas numphii used in the first 2 months and mixture
of wood charcoal and C. rumphii bulk at 1: 1 ratio used in the next duration were
favourable for D. ‘Zahra FR 62’ and D. ‘Gradita 31’. It was also mentioned that
plantlets could be grow better (90 – 100% plant survived)
by 50% net covering
to keep light intensity down to 100-150 μmol⋅m-2⋅s-1 and relative moisture at
85% – 95%.


8


promote the growth of D.officinal the sensity of 44 plant per square metter
and foliar Growmore application should be paid great attention and
reccommended.
CHAPTER 2
MATERIALS. CONTENTS AND METHODS OF STUDY
2.1. Materials
- Orchid accessions used in evaluation of morphological, micro operation


9

and bio-chemical analyse were D. loddigesii orchid collected and
screened in Dinh Hoa – Thai Nguyen province and D. aphyllum ones in
Hon Ba – Khanh Hoa province.
- Materials used in tissue culture were taken from bud tips of D. loddigesii
and D. aphyllum orchids with 7 - 10 cm high.
- Materials used in somatic embtyo creation were PLBs (protocorm like
bodies) formed from growth peak culture. At 6 weeks after cultured,
unique PLBs were cut into pieces of 3 – 4 mm long for synthetic seed
formation.
- In nursery period: in vitro plantlets multiplied from synthetic seeds of 5 –
6 cm high with 4 – 6 leaves and 3 – 5 roots.
- In production gardens: Plants of 6 – 7 cm high with 6 -7 leaves and 3 – 4
newly formed roots.
- Organic Juices extracted from tomato, pumpkin…
- Materials used in in vitro rapid multiplication: saccaroza, charcoal
- Media materials: Sphagnum moss, Pumice Stone, pine bark, coconut fibre
and “Don bang”…
- Nutritional sustances: Orchid Focus grow, Seaweed 95%, Striving buffalo
502, B1 Thai Lan, Growmore.

- Total alkaloid content determination was based on acid - base method
presented in (Vietnam Pharmacy IV, 2009).
- Total flavonoid content determination was based on UV-VIS method.
(Mudasir Sultana et al., 2012).
- Total polysaccharids content determination was based on UV-VIS
method (Chinese Pharmacy, 2010).
- Mineral (Ca, Mg, Fe) content determination was based on atomic absorb
spectrum (AAS).
2.3.2 Experimental design
- Experiment 1: Study on the effect of NaOCl and sterilized duration to
accession situation
- Experiment 2: Study on the effect of disinfectant cefotaxime to survival
ratio of explants cultured
- Experiment 3: Study on the effect of BA to PLBs formed from traverse
thin cell layers (tTCL)
- Experiment 4: Study on the effect of BA and αNAA compound to PLBs
formed from traverse thin cell layers (tTCL)
- Experiment 5: Study on the effect of combination (BA + IBA) on
regeneration of shoots from PLBs
- Experiment 6: Study on the effect of mashed pumpkin on regeneration
of shoots from PLBs
- Experiment 7: Study on the effect of Spirulina algae on regeneration of
shoots from PLBs
- Experiment 8: Study on the effect of IBA to root formation of the shoots
- Experiment 9: Study on the effect of PAA to root formation of the shoots
- Experiment 10: Study on the effect of sodium alginate concentration (%)
and CaCl2.2H2O (mM) to the formation and germination of synthetic seeds
- Experiment 11: Study on the effect of contacting duration with
CaCl2.2H2O solution to synthetic seed germination.
- Experiment 12: Study on the effect of BA and BA + IBA compound to

gardens
Criteria observed:
+ Root related criteria:
- Root number/quantity (a plant), root length (cm)
- Dissect criteria: bark dimension, zylem dimension, number and
dimension of vessel…
- Dimension of different tissues…
+ Leaf related criteria:
- Leaf shapes: oblong shape, tonge formed shape; sharp peak shape...leaf
lenth (cm), leaf width (cm)
- Micro dissect criteria: dimension of different tissues, numer and
dimension of vessel
+ Flower related criteria:
- Flower diametter (cm), length of flower shoot (cm), flower petal
dimension (cm): dimensions of different flower organs…
- Micro dissect criteria: pollen, stage….


12

+ Criteria observed in in vitro culture and synthetic seedcreation
Infected explant ratio (%), survived plant ratio (%), number of
PLBs/tTCL (PLBs) formed, ratio of PLBs formed (%), ratio of protocorm
formed explant (%), multiplication coefficience of protocorm, shoot height
(cm); number of leaf/shoot, germinated seed ratio (%), number of
shoot/seed, shoot length (mm), rooted seed ratio (%), number of root/shoot...
+ Growth and development criteria (nursery period and production
garden)
- Survived plant ratio (%), plant height (cm), plant stem diametter (cm),
number of leaf/plant, leaf length (cm), leaf width (cm), number of

and IRRISTAT 5.0 soft wears.


13

CHAPTER 3. RESULTS AND DISCUSSIONS
3.1 Biological characteristics of D. loddigesii and D. aphyllum
3.1.1 Morphological characteristics of D. loddigesii and D. aphyllum
orchids
Both D. loddigesii and D. aphyllum orchids have thin, filamentous and
aerial roots with cylendar form, blue colour and turn brown with time. Root
system of these species when grown in pots develop closely surrounding
media or bended downwards. Its have good capacity or regeneration, water
and nutrition exploitation from soil.
D. loddigesii and D. aphyllum have lots of long stems of many
internodes that consist one sleep bud each. Stems of D. loddigesii orchid are
thin, cylinder formed, bended with 40.2 cm long, 0.5 cm diametter whereas
oblong, cylinder formed and bended stems of 70.4 cm long and 0.8 cm
diameter were observed in D. aphyllum orchid.
Leaves of D. loddigesii orchid are wedge shaped and tounge formed
with sharp peak, dark blue colour, 5.0 cm long, 1.5 cm width. 17 leaves
available in a stem was also observed. D. aphyllum orchid has sharp peak,
look like leather with smooth edges. Its leaves are light blue coloured, soft
and thin, 7.62 cm long, 3.10 cm width with 32 leaves on a stem.
Flowers of D. loddigesii orchid are single, purple whitenish with yellow
colour in the centre. 1 – 2 flowers was found on a leaf existed stem. Flower
stalks are light blue, 0.4 – 0.8 cm long. Flowers of 5.2 cm diameter are
covered with thin and light purple coloured slides. Calyx petal are oblong
with shrpless peak and 2 side petals of 2.5 cm long and 0.7 cm width. Corola
petals are elip formed, 1.7 cm long and 1.0 cm width. Petal curved edges are

characters proves that the resistance to unfavourable conditions of D.
aphyllum is a little bit better than D. loddigesii orchid. And, because of that,
it is necessary to have good pergular for D. loddigesii when grown in the
gardens and tieing its shoots closely to strong supporters.…
Leaves of D. aphyllum orchid are thin and soft with large leaf blades
whereas D. loddigesii has hard and thick leaves, 2.5 times thicker than D.
aphyllum but the width of D. loddigesii leaf blade is much lower than D.
aphyllum. It is also found that the thickness of assimilative tissues of Nghe
tam is 2.78 times thiker than D. aphyllum whereas the same dimension of
liber vessels located in main veins was also recorded.
Flowers of D. loddigesii orchid are single ones, purplish white and
yellow in the centre, sprouted on leaf existed stems covered by light purple
coloured slides. Calyx petals are oblong with sharpless peaks, side petals of
2.2 – 2.5 cm long and o.7 cm width are bigger than opposite ones (1.6 – 1.9
cm long; 0.7 – 0.8 cm width). Corola petals are oval, nearly round peaks, 1.6
– 1.7 cm long, 0.8 – 1.0 cm width) whereas lip petals have white colour in
curved edges yellow in th ecentre, 1.7 – 1.9 cm long and 2.1 – 3.1 width
diveded into 3 lobes of yellow colour with smooth hairs in the centre. Lip
petals are closely placed with stamen at the bases. State axil is short and
semi cylinder formed, 0.7 – 0.8 long whereas stigma with three spaces is
light green, 3.1 – 3.5 cm long. Pollen with sharp cover is located at the peak
and devided into 2 blocks of 4 pollen spaces each.
Flower of D. aphyllum orchid is single one or cluster of 2 – 3 flowers,
sprouted from non leaf existed stem with white colour and dark purple in the
centre. Three calyx petals have same dimension including 2 side petals of
2.7 – 3.6 cm long; 0.7 – 0.9 width and opposite petal of 2.5 – 3.1 cm long;
0.6 – 0.7 width. Corola petal is oblong with almost sharp peak, 2.7 – 3.1 cm
long and 1.0 – 1.1 width whereas lip petal was observed as round shaped one



5
6
7

Total Alkaloid (%)
Total Flavonoid (%)
Total Polysaccharid (%)
Protein (%)
Ca(mg/kg)
Mg(mg/kg)
Fe(mg/kg)

0.35
0.92
1.42
6.0
12030
1726
168

0.35
0.56
4.2
6.6
14821
2829
134

3.2 Study on in vitro propagation, synthetic seeds creation techniques
and in vitro multiplication from preserved synthetic seeds of D.

Dl
Da
Dl
Da
1.5
0(Đ/C)
52. 03
30.40
30.12
17.83
1.5
0.5
38.0
49.22
21.00
28.71
1.5
1.0
31.0
38.30
19.00
20.70
1.5
1.5
21.9
19.96
12.80
12.30
1.5
2.0



17

Supply of mashed pumpkin juice to medium promoted significantly
shoot regeneration presented by increasing the number of shoot created. In
the medium of VW + 20 g/l sucrose + 10% coconut water + 7 g/l agar +1 g/l
activated charcoal + 2 g/l peptone + 1,5 mg/l BA + 0,5 mg/l IBA added with
30 g/l mashed pumpkin, 10.6 shoots regenerated/a sample of 4.20 cm high
(for D. loddigesii) and 11.6 shoots regenerated/a sample of 4.43 cm high (for
D. aphyllum) were observed at 6 weeks after cultured. It is, however,
reported that number of shoot created was oriented to decrease if 30 g/l up
concentration was supplied.
3.2.3.3 Effect of Spirulina algae powder on regeneration of shoots from
PLBs
Data in table 3.13 showed that: adding 1 g/l Spirulina algae to medium
of VW + 20 g/l sucrose + 10% coconut water + 7 g/l agar + 1 g/l activated
charcoal + 2 g/l peptone + 1,5 mg/l BA + 0,5 mg/l IBA + 30 g/l mashed
pumpkin with pH of 5.5 gave the best effect to regeneration of shoot from
PLBs.
Table 3.13. Effect of Spirulina algae powder on regeneration of shoots
from PLBs (8 weeks after cultured)
Mashed
Spirulina No. shoots/
Shoot
explant
height (cm)
pumpkin
algae
Shoot situation

14.50

14.60

5.00

5.10

30

3

11.24

11.30

4.50

4.46

3.6
2.16

3.0
1.02

2.9
1.42

3.3

the growth of young plants, plants of 6.5 cm high with 5.3 leaves and 7.3 roots
each, long and chubby roots with 2.87 cm long were recorded at 6 weeks after
cultured (Table 3.14).
In case of D. aphyllum (Table 3.15), supplying 0,5 mg/l PAA gave the
best result, presented by plant height (6.96 cm), leaf and root number (5.7
leaves and 7.4 roots/a plant) root length (3.02 cm) at 6 weeks after cultured,
a little bit better than supplying with 1 mg/l IBA.
Table 3.14 Effect of IBA to root formation of orchid in vitro shoots (6
weeks after cultured)
IBA
concentrations
(mg/l)
0,0 (Đ/C)
0.5
1.0
1.5
2.0
CV (%)
LSD0,05

Plant
height
(cm)

Dl

Da

3.50 3.52
5.30 5.38

3.00
4.20
5.30
4.08
4.00
4.1
0.6

3.00
4.50
5.40
4.10
3.90
3.0
0.38

2.50
6.20
7.30
4.90
3.70
3.7
0.32

2.50
6.00
7.00
5.10
4.10
3.8

0.5
1.0
1.5
2.0
CV (%)
LSD0,05

Dl
3.53
6.16
5.42
5.10
4.20
3.3
0.79

Da
3.52
6.96
5.50
5.22
4.60
3.3
0.31

Dl
3.00
5.18
5.46
5.08

Da
2.50
7.40
5.90
5.20
4.50
3.2
0.46

Root
length
(cm)

Dl
1.10
2.46
2.00
1.30
0.92
2.7
0.91

Da
1.15
3.02
2.20
1.60
1.03
3.1
0.19

aphyllum respectively). The growth of shoots sprouted from these seeds of
D. loddigesii and D. aphyllum were also healthy stored by shoot height (4,15
cm and 4.0 cm), rooted shoot percentage (68.2% and 70.0%), root number/a
seed (2.6 and 3.0) respectively at 16 weeks after stored.
3.2.6.2 Effect of ABA to to stored duration of synthetic seeds
Supply of ABA 20 mg/l gave the best effect to synthetic seed
germination (51.1% for D. loddigesii and 50.02% for D. aphyllum at 24
weeks after preserved). After 24 weeks of preservation, germination of
synthetic seed was decreased with time.
3.2.6.3 Effect of Natri benzoat, topsin-M and carbendazim to survival of
preserved synthetic seeds
Of three preservative substances mixed with artificial films,
carbendazim at 3000 mg/l concentration gave the best effect, better than natri
benzoat and topsin-M, low infected seed ratio and high germinated one
(68.2% for D. loddigesii and 70.2% for D. aphyllum at 24 weeks after
preserved) were observed. It is, however, obvious that at too low (0.
200mg/l) or too high (4,000 mg/l up) concentrations, high ratio of infected
seeds and low ratio of germinated seeds were also recorded.


20

3.2.7 Study on in vitro propagation of preserved synthetic seeds
3.2.7.1 Effect of BA + PAA compound to rapid multiplication of protocorm
and shoots from preverved synthetic seeds
VW medium supplemented with 1,5 mg/l BA + 0,5 mg/l PAA was
considered the most appropriate for propagation of protocorm and preserved
synthetic seeds presented by number of protocorm produced (8.5 for D.
loddigesii and 8.3 for D. aphyllum), number of shoots created (7.5 for D.
loddigesii and 7.3 for D. aphyllum) and shoot height (4.3 cm for D.

Dl
Da shoot
(g/l)
0,0 (Đ/C)
8.50
8.40
7.40
7.20
4.40
4.30 +++
10
9.50
9.80
7.90 9.40
4.70
4.60 +++
30
10.20
10.10
8.10 10.10 4.90
4.80 +++
50
10.40
11.20 10.90 10.50 5.20
5.30 ++++
70
12.80
16.60 12.30 12.90 5.40
5.60 ++++
100


3.2.8 Study on in vitro complete plant production from preserved
synthetic seeds
Adding 0,5 mg/l PAA to VW + 20 g/l sucrose + 7 g/l agar + 10%
coconut water + 1 g/l activated charcoal medium at pH of 5,5 gave the best
effect to rooting process of young plants before moving to nursery.
3.3 Study on management of in vitro plants of D. loddigesii and D.
aphyllum in nursery period
3.3.1 Growth comparision of in vitro plantlets multiplicated from shoot
and from preserved synthetic seeds in nursery period
Height of plants multiplicated from synthetic seeds was significantly at
5% level lower than that of plants traditionally propagated by in vitro culture
method (6.63 cm; 6.58 cm in the first method and 7.10 cm; 7.00 cm in the
later at 12 weeks after grown for D. loddigesii and D. aphyllum respectively)
No difference of numbers of newly produced of leaves and roots was
reported. It is also mentioned that young plants produced by these methods
were quite familiar in morphological characteristics in terms of colours and
shapes of stem, leaf and root etc…
3.4.2 Study on determination of suitable time for moving in vitro plants
to nursery
Table 3.29 Effect of plant moved seasons to survival and growth of in
vitro plants in nursery period
(12 weeks after planted)
Survived
Plant height
Number of
New roots/a
plant ratio
Seasons
(cm)

74.0
6.42
6.54
5.80
6.10
2.73
2.50
Spring
(18/02/2017)
76.00
75.0
6.86
6.70
6.03
6.23
3.00
2.80
Summer
(18/5/2017)
4.4
3.9
4.8
4.6
3.7
3.8
CV (%)
0.24
0.22
0.15
0.19

Number of newly
Fertilisers
(cm)
leaves
produce roots
Dl
Da
Dl
Da
Dl
Da
Water (Control)
6.00
6.50
5,79
5.51
1.93
1.83
B1- Thailand
9.10
8.76
7,93
8.13
4.60
5.30
Growmore
8.30
8.20
7,48
7.82

3.4.1 Study on determination of suitable media for orchid in production
gardens


23

For D. loddigesii orchid, medium of pine bark + Pumice Stone +
Sphagnum moss (40 : 40 : 20) characterized by light, well spongy and
ventiolated was recorded suitable for plant growth 913.35 cm high; 0.37 cm
diameter, 1,2 twigs; 9.6 leaves of 5.05 cm long and 1.29 cm width).
For D. aphyllum orchid, “Don bang” medium gave the best effect to
plant growth presented by healthy plants (13.46 cm high; 0.41 cm in
diametter), twig produced (1.1); lots of healthy leaves (9.7 leaves of 4.98 cm
long and 1.35 cm width) and good look.
3.4.2 Study on nutrional regime for orchid in production gardens
On the basic medium mentiond in part 3.4.1, adding B1 Thailand + sea
weed 95% promoted significantly the growth of orchid plan, better than other
compounds such as B1 Thailand + Grow more or B1 Thailand + Orchid
focus Grow. The healthiest plants were also recorded in this treatment.
3.4.3 Study on supplying Superthrive for orchid plants in production
gardens
Adding Superthrive with 0.2 ml/l dose impacted positively to orchid plant
growth of both species, plant height (18.4 cm for D. loddigesii; 23.7 cm for
D. aphyllum at 6 weeks after planted) and stem diametter (1.06 cm for D.
loddigesii; 1.21 cm for D. aphyllum at 6 weeks after planted) were much
higher than control (no adding) and applied with 0.1 ml/l Superthrive. In
addition, more twigs and leaves produced, healthier leaves presented by leaf
dimensions were also reported in this treatment.
CONCLUSIONS AND RECOMMENDATIONS
Conclusions