Nghiên cứu cải tiến các giống đậu tương DT2008, DT96 và đt26 bằng phương pháp xử lý đột biến tia gamma nguồn co60 tt tiếng anh

i
MINISTRY OF EDUCATION
MINISTRY OF AGRICULTURE
AND TRAINING
AND RURAL DEVELOPMENT
VIETNAM ACADEMY OF ARICULTURAL SCIENCES

---------------------------*-------------------------

NGUYEN VAN MANH

RESEARCH ON IMPROVING SOYBEAN VARIETIES DT2008,
DT96 AND ĐT26 THROUGH 60Co GAMMA IRRIGATION

Research: Genetics and Crop breeding
Code: 9620111

DOCTORAL THESIS SUMMARY OF AGRICULTURE

Hanoi - 2020


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The Doctoral thesis was completed in:
VIETNAM ACADEMY OF AGRICULTURAL SCIENCES
Supervisors:
1. Prof. PhD. Le Huy Ham
2. PhD. Le Duc Thao

Objection 1: ..... ……………………………
Objection 2: ..... ……………………………

Objection 3: ..... ………………………….

The Doctoral thesis is defended at Institute Committee of PhD Dissertation
Examination:
Vietnam Academy of Agricultural Sciences
At ………………..day……………month…………..2020.

PhD thesi can be found at:
1. National Library of Vietnam
2. Library of Vietnam Academy of Agricultural Sciences


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INTRODUCTION
1. Imperativeness of the thesis
Soybean (Glycine max (L.) Merrill), a short-day crop, has high nutrient
content (Protein 30 - 45%, lipit 18 – 22%...), easy cultivation, wide adaptation,
effect on land reclamation and insect limitation in the rotation of other crops.
In Vietnam, soybean is a traditional crop and grown in 28 of 63
provinces/cities. It plays an important role in agricultural production and has
high economic value and efficiency in crop restructing but its area is
decreasing. In 2018, soybean production reached at only 53.1 thounsand
hecta with the productivity of 80.8 thounsand tons (),
only met about 8% of domestic demand, the rest had to imported. The causes
of decrease in soybean production are the lack of soybean varieties with high
yield, good quality and good resistance; difficult condition of cultivation;
backward cultivation techniques and low intensive investment. Therefore, it
is urgent and necessary to create new soybean varieties with high yield, good
quality and suitable for many different crops. In soybean, it is hard to
eliminate anthers because its flowers are small, perishable and vulnerable. In

addition, its completely self-fertilization results in being difficult to create
heritable variations by hybridization.
Therefore, mutation method through 60Co gamma irradiation is so
efficient to generate new heritable variations in soybean, contributing to
diversifying genetic variations, shortening the time to select a new variety,
and especially improving existing soybean varieties. In order to diversity
soybean varieties in production, contributing to expanding the area and
developing soybean production in Vietnam, the thesis “Research on
improving soybean varieties DT2008, DT96 and ĐT26 through 60Co gamma
irradiation” has been carried out.
2. Objectives
Improving soybean varieties in the goals of shortening the growth
duration and stem height, increasing the resistance to lodging and seed
quality…through 60Co gamma irradiation to create and select new soybean
varieties, meeting the demand of current production.
3. Scientific and Practical Significances
3.1. Scientific Significances
Results of the thesis would be the basic for creating new soybean
varieties by mutation method through 60Co gamma irradiation in the goals of
shortening the growth duration and stem height, increasing the resistance to
lodging and seed quality…
Through conducting the thesis, the highly effective irradiation doses


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of gamma ray (60Co) have been identified for creating new mutant soybean
varieties.
The data published in this work can be used as a guide material for
teaching and research on soybean breeding in agricultural universities and
research institutes.

3.2. Practical Significances
New soybean mutants including 01 self- declared circulation variety
DT215 and 02 promising lines DT96ĐB and ĐT26ĐB have been created.
They have high yield (>2.5 tons/ha), good quality (protein > 40%, lipid
>18%), good resistance to rust and powder mildew, meeting the demand of
current production.
The group of 234 mutant soybean lines in the M7 generation divided
from soybean virieties DT2008, DT96 and ĐT26 with improved traits are
signigicant materials for creating and selectiong new soybean varieties.
4. Research Materials and Scope
4.1. Research Materials
Soybean varieties DT2008, DT96 and ĐT26.
Mutagen of gamma ray from the source of Cobalt 60 (60Co).
4.2. Research Scope
Creating soybean mutants through gamma irradiation (Co60) on dry
seeds, germination seeds and flowering plants.
Evaluating the impact of gamma irradiation (Co60) on the growth and
development of the soybean varieties.
Selecting new soybean lines significant for creating and selecting
new soybean varieties.
Testing and trial production of new promising mutant soybean
varieties.
5. Significant Contribution
Effective gamma irradiation doses (60Co) in soybean have been
indentified at the doses of 150Gy, 200Gy and 250Gy on dry seeds, 25Gy and
50Gy on germination seeds and 10Gy and 20Gy on flowering plants.
A collection of 234 mutant soybean lines with one or some improved
traits compared to the original varieties such as growth duration, stem height,
seed cover colour… have been created and used as significant materials for
new soybean breeding.

A new mutant soybean variety DT215 (the yield of 2.71 – 3.32
tons/ha but black seed coat different from DT2008’s yellow seed coat, 5 – 10
days shorter growth duration in the range of 90 – 95 days) which was selfrecognized for introducing into the production and 2 promising mutant


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soybean varieties DT96ĐB (the growth duration of 90 – 94 days, the height
of 52.1 – 59.9 cm and the yield of 2.22 – 3.06 tons/ha but better lodging
resistance compared to the origin DT96) and ĐT26ĐB (the yield of 2.23 –
2.55 tons/ha but black seed coat different from ĐT26’s yellow seed coat, the
growth duration of 86 – 91 days) have been produced. They have good
growth and development, good resistance to deseases, high yield… and
satisfy the demand of current produciton.
6. Thesis structure
The thesis consists of 140 pages (excluding illustrations and
Appendices) including Introduction (4 pages); Chapter 1: Literature Review
(35 pages); Chapter 2: Materials, Contents and Research Methods (12 pages);
Chapter 3: Research Results and Discussion (68 pages); Conclusions and
Recommendations (2 pages); List of published works related to the thesis (1
page); References (18 pages) with 85 Vietnamese documents, 49 English
documents and 3 websites. The thesis has 53 data tables, 12 pictures, 35
appendices and 6 published works.
CHAPTER I. LITERATURE REVIEW
The literature review presents the following contents of (1) Introduction
of soybean, (2) Research situation of soybean breeding in the world and in
Vietnam, (3) Mutaiton and applications in plant breeding, (4) Research on
mutant soybean breeding. Thereby, some following comments have been drawn:
Soybean is the main source of protein and vegetable oil for the whole
world. It is used as food for human and livestocks, for soil conditioning… In
Vietnam, soybean is a traditional crop but its production has met only about 8%

of domestic demand with the decrease in area because of low yield, backward
cultivation techniques, low investment, especially the lack of new soybean
varieties…
Mutation method is so effective to improve plant varieties and has created
over 3,200 varieties of 220 plant species. It has produced a rich source of genetic
variation, especially unavailabe traits in nature. In Vietnam, there has been 61
mutant crop varieties of rice, flower, soybean…
Currently, there has been 171 mutant soybean varieties in the world,
mainly created through gamma irradiation (66 varieties) with the improved traits
of yield, growth duration, stem height, seed coat colour and resistance. In
Vietnam, there has been 11 mutant soybean varieties, of which 8 varieties created
through gamma irradiation such as DT84, DT90, DT99, DT2008, AK06…
However, these varieties has been mainly created through gamma irradiation on
dry seeds. There has been still the limitation on studies of gamma irradiation on
germination seeds and flowering plants have been still limited.


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CHAPTER II.
MATERIALS, CONTENTS AND RESEARCH METHODS
2.1. Materials
2.2.1. Soybean varieties: DT2008, DT96, ĐT26 and DT84 (control)
2.2.2. Mutagenic agent: 60 Cobalt source (60Co) of gamma ray
- Irradiation doses on dry seeds: 0 (control), 100, 150, 200, 250, 300 and
350 Gy.
- Irradiation doses on germination seeds: 0 (control), 25, 50, 75, 100, 125
and 150 Gy.
- Irradiation doses on flowering plants: 0 (control), 10, 20, 30, 40, 50 and
60 Gy.
2.2. Contents

Content 1: Research on the effect of gamma irradiation (60Co) on the
growth and development of soybean varieties.
Effect of gamma irradiation (60Co) on the growth and development of
soybean varieties.
Effect of gamma irradiation (60Co) on variation frequency and spectrum
of soybean varieties.
Evaluating the inheritance of morphological variations derived from
soybean varieties which were irradiated with gamma ray (60Co).
Content 2: Research on selecting significant mutant soybean lines for
soybean breeding
Selecting mutant individuals and soybean lines significant for soybean
breeding.
Evaluating and comparing promising mutant soybean lines.
Evaluating the genetic diversity of some mutant soybean lines by SSR
markers.
Content 3: Testing the production trials of promising mutant soybean
varieties.
2.3. Research Methods
2.3.1. Gamma irradiation method soybean varieties DT2008, DT96 and ĐT26
a) Gamma irradiation on dry seeds
Dry seeds of soybean varieties were irradiated at the doses of 0 (control),
100, 150, 200, 250, 300 and 350 Gy with the source power of 64.8 kCi during
30 minutes. Each treatment used 600 seeds.
b) Gamma irradiation on germination seeds
Dry seeds of soybean varieties were soaked in fresh water during 2
hours, and then put into the incubator at 260C during 2, 4, 6, 8 and 10 hours. The
seeds after incubating were irradiated at t0he doses of 0 (control), 25, 50, 75, 100,
125 and 150 Gy during 30 minutes with the source power of 62.3 kCi. Each

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treatment used 500 seeds..
c) Gamma irradiation on flowering plants
Dry seeds of soybean varieties were sown in pots. At the blooming stage
(50% of plants in bloom), flowers, pods and buds on each plant of pots were
marked with thread separately and irradiated at the doses of 0 (control), 10, 20,
30, 40, 50 and 60 Gy during 30 minutes, the source power of 61.1 kCi. Each
treatment used 3 pots.
2.3.2. Research on the effect of gamma irradiation (60Co) on the growth and
development of soybean varieties
a) Experimental design
Treatments were designed in sequence without replication and with the
alternation of the controls of original varieties. The plot area was 8.5 m2 (5m x
1.7m). Seeds were sown in the density of 35-40cm in row distance and 10cm in
hole distance, one seed per hole.
* M1 generation:
Gamma irradiation on dry seeds: After irradiaton, 100 seeds of each
treatment were taken and sown on the tray with sterilized sand at 26oC during 7
days to evaluate the germination rate. The remaining seeds of each treatment
were sown in the experimental field to evaluate the growth and development. At
the harvesting stage, variant individuals were collected separately. The mixture
of remaning plants were collected in each treatment.
Gamma irradiation on germination seeds: Seeds after irradiation were sown
in the experimental field to evaluate the growth and development. At the
harvesting stage, variant individuals were collected separately. The mixture of
remaning plants were collected in each treatment.
Gamma irradiation on flowering plants: After irradiaton, soybean
varieties were observated and evaluated on the growth and development in green
house. At harvesting stage, seeds from marked flowers, pods and buds were
collected separately in each treatment.

* M2 generation:
Seeds collected from M1 generation were sown in M2 generation in each
treatment. Seeds of M1 individuals were sown in separate rows.
b) Effect of gamma irradiation (60Co) on germination and survival rate of
soybean varieties
c) Effect of gamma irradiation (60Co) on the growth and development of soybean
varieties
The growth and development of soybean varieties were observed
continuously from seedling stage to harvesting stage on traits of stem height, a
number of branches, a number of pods, a number of fertile pods, 1000-seed
weight….


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d) Effect of gamma irradiation (60Co) on variation frequency and spectrum of
soybean varieties
Observating and detecting morphological variations and agronomic
traits such as leaflet shape, stem colour, seed coat colour, growth duration, stem
height….
e) Evaluating the inheritance of morphological variations derived from soybean
varieties irradiated with gamma ray (60Co)
The inheritance of morphological variations was evaluated and
monitored over generations M1 to M2, M2 to M3 and M3 to M4.
2.3.3. Research on selecting significant mutant soybean lines for soybean
breeding
a) Research on selecting significant mutant soybean lines for soybean breeding
Pedigree method was used to select mutant soybean lines based on bioagrobiological traits such as stem shape, leaflet shap, pubescence colour, growth
duration, lodging resistance, 1000-seed weight, seed coat colour…
b) Evaluating and comparing promising mutant soybean lines
Promising mutant soybean lines were evaluated and compared under the

national standard QCVN 01-58:2011/BNNPTNT by Ministry of Agriculture and
Rural Development on the value of cultivation and use of soybean varieties.
Experiments of comparing mutant soybean lines were designed in RCB
with three replications on the plots with the area of 8.5 m2.
c) Evaluating the genetic diversity of some mutant soybean lines by SSR markers
2.3.4. Testing the production trials of promising mutant soybean varieties
Promising mutant soybean varieties were tested under the national
standard QCVN 01-58:2011/BNNPTNT by Ministry of Agriculture and Rural
Development on the value of cultivation and use of soybean varieties.
2.3.5. Analysis of grain nutrition content
2.3.6. Observation traits
Observation traits and evaluation methods under the national standard
QCVN 01-58:2011/BNNPTNT by Ministry of Agriculture and Rural
Development on the value of cultivation and use of soybean varieties.
2.3.7. Data Analysis
Data analysis was processed by Excel 2016 and IRRISTAT 5.0.
2.4. Research time and place
2.4.1. Research time
From 2012 to 2019.
2.4.2. Research place
Field experiments were conducted in Dan Phuong district, Hanoi city.
Production trials of promising mutant soybean varieties were conducted
Hanoi, Vinh Phuc...


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CHAPTER III. RESEARCH RESULTS AND DICUSSIONS
3.1. Research on the effect of gamma irradiation (60Co) on the growth and
development of soybean varieties
3.1.1. Research on the effect of gamma irradiation (60Co) on the growth and

development of soybean varieties irradiated on dry seeds
a) Effect of gamma irradiation (60Co) on germination and survival rate of
soybean varieties irradiated on dry seeds
There was a little effect of gamma irradiation on germination rate in
M1 and M2 generations in soybean varieties irradiated on dry seeds. The
germination rate ranged from 98 to 100% (the rate of 100% at the control) in
M1 generation and from 98.3 to 100% (the rate of 100% at the control) in M2
generation.
Table 3.1. Effect of gamma irradiation (60Co) on germination rate of soybean
varieties in M1 and M2 generations
Unit: %
M
generation
M
generation
1
2
Radiation
doses
DT2008 DT96 ĐT26 DT2008 DT96 ĐT26
0Gy (control)
100
100
100
100
100
100
100Gy
100
100

100
100
100
99.7
150Gy
100
100
100
98.7
99.7
100
200Gy
99.0
99.0
99.0
100
99.7
99.3
250Gy
100
100
100
99.0
98.7
99.7
300Gy
99.0
98.0
99.0
99.3

99.3
99.3
350Gy
98.0
99.0
100
99.3
98.3
98.7
The survival rate of soybean varieties decreased with the increase of
radiation doses. The effect of gamma irradiation on survival rate was much
in M1 generation but little in M2 generation. In M1 generation, survival rate
decreased rapidly with the increase of radiation doses from 200 Gy to 350
Gy. The survival rate in soybean variety DT2008, DT96 and ĐT26 ranged
from 26.4-94.2% (the rate of 97.6% at the control), 20.8-94.0% (the rate of
94.6% at the control) and 20.2-96.2% (the rate of 96.4% at the control)
respectively. Lethal dose 50% (LD50) was indentified at 300 Gy. In M2
generation, the survival rate in soybean variety DT2008, DT96 and ĐT26
ranged from 81.9-85.7% (the rate of 85.2% at the control), 73.7 – 81.1% (the
rate of 80.6% at the control) and 78.3 – 83.2% (the rate of 83.1% at the
control) respectively.


8
Table 3.2. Effect of gamma irradiation (60Co) on survival rate of soybean
varieties irradiated on dry seeds in M1 and M2 generations
Unit: %
M1 generation
M2 generation
Radiation

doses
DT2008 DT96 ĐT26 DT2008 DT96 ĐT26
0Gy (control)
97.6
94.6
96.4
85.2
80.6
83.1
100Gy
94.2
94.0
96.2
85.7
81.1
83.2
150Gy
89.6
87.4
91.6
85.3
74.5
83.1
200Gy
81.4
73.6
84.4
85.0
76.8
82.1

250Gy
68.2
56.8
68.4
84.6
74.9
81.8
300Gy
45.6
39.4
45.2
82.3
74.6
80.6
350Gy
26.4
20.8
20.2
81.9
73.7
78.3
60
b) Effect of gamma irradiation ( Co) on growth and development indicators of
soybean varieties irradiated on dry seeds
Gamma irradiation on dry seeds prolonged the growth duration and
reduced quantity traits such as stem height, a number of fertile pods,
individual yield....in soybean varieties. The decrease of quantity traits was
much in M1 generation but little or negligible in M2 generation.
c) ) Effect of gamma irradiation (60Co) on variation frequency and spectrum of
soybean varieties irradiated on dry seeds

50

100
50

0

0
0 100 150 200 250 300 350
(Đ/c) M1 generation
DT2008

DT96

0 100 150 200 250 300 350
(Đ/c)

M2 generation
DT2008
DT96

ĐT26

ĐT26

Figure 3.1. Effect of gamma irradiation (60Co) on variation frequency of
soybean varieties irradiated on dry seeds in M1 and M2 generations
Variation frequency was on the increase of radiation doses from 100
Gy to 350 Gy. In M1 generation, variation frequency of soybean varieties
DT2008, DT96 and ĐT26 ranged from 0.6 – 58.8% (the rate of 0.4% at the

control), 0.2 – 54.6% (the rate of 0.2% at the control) and 0.4 – 52.6% (the
rate of 0.2% at the control) respectively. In M2 generation, variation
frequency of soybean varieties DT2008, DT96 and ĐT26 ranged from 6.1 –
36.1% (the rate of 0.8% at the control), 6.4 – 39.8% (the rate of 0.6% at the
control) and 6.4 – 37.7% (the rate of 0.5% at the control) respectively.


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Table 3.10. Effect of gamma irradiation (60Co) on variation spectrum of
soybean varieties irradiated on dry seeds in M1 and M2 generations
Unit: number of variations
M1 generation
M2 generation
Radiation
doses
DT2008 DT96 ĐT26 DT2008 DT96 ĐT26
0Gy (control)
2
1
1
1
1
1
100Gy
2
1
2
2
5
6

150Gy
6
7
7
7
14
8
200Gy
9
9
9
14
14
14
250Gy
8
8
7
10
14
11
300Gy
5
5
6
5
4
2
350Gy
4

4
4
5
3
2
Gamma irradiation on dry seeds produced many variations in M 1 and
M2 generations such as stem shape (curved or flat stem…), branch shape
(early branching, symmetrical branching…), leaflet shape, seed coat colour,
pubescence colour… Variation spectrum was on the increase with increasing
doses from 100 Gy to 200 Gy and on the decrease at the dose of 300 Gy. In
M1 generation, the number of variations of soybean varieties DT2008, DT96
and ĐT26 ranged from 2-9, 1-9 and 2-9 respectively. In M2 generation, the
number of variations of soybean varieties DT2008, DT96 and ĐT26 was
more than in M1 generation and ranged from 2-14, 3-14 and 2-14
respectively. The radiation dose with the most number of variations was 200
Gy (9 variations in M1 generation and 14 variations in M2 generation),
followed by the doses 250 Gy (7-8 variations in M1 generation and 10-14
variations in M2 generation) and 150 Gy (6-7 variations in M1 generation and
7-14 variations in M2 generation). There were a little number of variations at
the doses 100, 300 and 350 Gy. In particular, there were some significant
variations for soybean breeding in M2 generation such as straight stem (acuteangled branching angle), branchiness, black seed cover, fruitfulness, early
maturation…
3.1.2. Research on the effect of gamma irradiation (60Co) on the growth and
development of soybean varieties irradiated on germination seeds
a) Effect of gamma irradiation (60Co) on germination and survival rate of
soybean varieties irradiated on germination seeds
In M2 generation, the germination rate of soybean varieties DT2008,
DT96 and ĐT26 at treatments was equal to the control, ranged from 98.7-

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99.7% (the rate of 99.5% at the control), 98.7-99.5% (the rate of 99.8% at the
control) and 98.7-99.7% (the rate of 99.9% at the control).
Table 3.12. Effect of gamma irradiation (60Co) on germination rate of soybean
varieties in M1 and M2 generations
Unit: %
M
generation
M
generation
1
2
Radiation
doses
DT2008 DT96 ĐT26 DT2008 DT96 ĐT26
0Gy (control)
96.2
92.4
95.1
84.8
82.1
83.2
25Gy
91.4
87.4
90.0
83.7
81.7
81.0
50Gy

79.2
75.0
78.0
82.4
80.1
79.4
75Gy
58.8
54.3
56.7
81.1
78.9
78.2
100Gy
41.2
37.1
39.2
80.2
77.9
77.3
125Gy
27.0
23.0
25.4
80.1
78.5
76.9
150Gy
12.3
8.1

10.8
78.0
74.9
74.8
The survival rate of soybean varieties at treatments was lower than that
at the control and on the decrease with the increase of radiation doses from
25 Gy to 150 Gy, and was the lowest at 150 Gy. The effect of gamma
irradiation on the survial rate in M1 generation was higher than in M2
generation. In M1 generation, the survival rate of soybean varieties DT2008,
DT96 and ĐT26 ranged from 12.3 – 91.4% (the rate of 96.2% at the control),
8.1 – 87.4% (the rate of 92.4% at the control) and 10.8 – 90.0% (the rate of
5.1% at the control) respectively. Lethal dose 50% (LD50) was indentified at
100 Gy. In M2 generation, the survival rate of soybean varieties DT2008,
DT96 and ĐT26 ranged from 78.0 – 83.7% (the rate of 84.8% at the control),
74.9 – 81.7% (the rate of 82.1% at the control) and 74.8 – 81.0% (the rate of
83.2% at the control). There was a little effect of different incubation times
on the survival rate.
b) Effect of gamma irradiation (60Co) on growth and development indicators of
soybean varieties irradiated on germination seeds
Gamma irradiation on germination seeds prolonged the growth duration
and reduced quantity traits such as stem height, a number of fertile pods,
individual yield....in soybean varieties. The higher the dose of gamma
irradiation was, the greater the effect of gamma irradiation on growth and
development was in M1 generation. There was no difference of growth and
development among treatments and the control in M2 generation.
c) Effect of gamma irradiation (60Co) on variation frequency and spectrum of
soybean varieties irradiated on germination seeds


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Variation frequency of soybean varieties was on the increase with the
rise in gamma irradiation dose. In M1 generation, variation frequency of
soybean varieties DT2008, DT96 and ĐT26 ranged from 24.1 – 100, 25.3 –
100.0 and 20.4 – 100% (the rate of 0% at the control) respectively. From
100Gy and over doses, variation frequency was 100% (mainly sterile
variations and late maturation). In M2 generation, variation frequency of
soybean varieties DT2008, DT96 and ĐT26 ranged from 10.3 – 58.1, 23.9 –
88.0 and 16.9 – 68.7% respectively. There was a little effect of different
incubation times on the variation frequency in soybean varieties.
200

100

100

50

0

0

DT2008

DT96

ĐT26

DT2008

DT96

ĐT26

M1 generation
M2 generation
Figure 3.2. Effect of gamma irradiation (60Co) on variation frequency of
soybean varieties irradiated on germination seeds in M1 and M2 generations
Table 3.18. Effect of gamma irradiation (60Co) on variation spectrum of
soybean varieties irradiated on dry seeds in M1 and M2 generations
Unit: number of variations
M
generation
M2 generation
1
Radiation
doses
DT2008 DT96 ĐT26 DT2008 DT96 ĐT26
0Gy (control)
0
0
0
4
3
4
25Gy
10
10
10
17
17

16
50Gy
10
10
10
17
17
16
75Gy
10
10
10
14
13
16
100Gy
7
7
7
12
9
13
125Gy
7
7
7
8
10
10
150Gy

7
6
6
9
9
9
A number of variations of soybean varieties ranged from 7-10 in M1
generation and 8-17 in M2 generation. In M1 generation, the number of
variations of soybean varieties DT2008, DT96 and ĐT26 ranged from 7-10,
6-10 and 6-10, respectively. There was no variation at the control. In M2
generation, the number of variations of soybean varieties DT2008, DT96 and
ĐT26 ranged from 8-17, 9-17 and 9-16, respectively. The radiation dose with


12
the most number of variations was 25 and 50 Gy (the number of variations
was 10 in M1 generation and 16-17 in M2 generation. At the same irradiation
dose, there was no effect of incubation times on variation spectrum in
soybean varieties. Some significant variations for soybean breeding were
selected such as straight stem (acute-angled branching angle), short stem,
branchiness, early maturation…
3.1.3. Research on the effect of gamma irradiation (60Co) on the growth and
development of soybean varieties irradiated on flowering plants
a) Effect of gamma irradiation (60Co) on germination and survival rate of
soybean varieties irradiated on flowering plants
Table 3.19. Effect of gamma irradiation (60Co) on germination rate of soybean
varieties irridiated on flowering plants in M2 generation
Unit: %
M1 generation
M2 generation

Radiation
doses
DT2008 DT96
ĐT26 DT2008 DT96 ĐT26
0Gy (control)
99.6
99.1
99.3
93.2
90.6
94.8
10Gy
99.2
99.3
99.0
79.3
73.8
81.6
20Gy
98.5
98.5
98.2
41.2
31.2
39.9
30Gy
98.4
98.5
98.4
22.5

21.5
20.6
Note: No seed harvested at the doses of 40, 50 and 60Gy M1 generation
The plants irradiated at the doses 40, 50 and 60 Gy were sterile and
didn’t have any seed in M1 generation. In M2 generation, the germination rate
of soybean varieties DT2008, DT96 and ĐT26 ranged from 98.4 – 99.2%
(the rate of 99.6% at the control), 98.5 – 99.3% (the rate of 99.1% at the
control) and 98.2 – 99.0% (the rate of 99.3% at the control), respectively.
The survival rate of soybean varieties at treatments was lower than
that at the control and on the rapidly decrease with the increase of radiation
doses from 10 Gy to 30 Gy (No seed harvested at the doses of 40, 50 and
60Gy M1 generation), and was the lowest at 30 Gy. The survival rate of
soybean varieties DT2008, DT96 and ĐT26 ranged from 22.5 – 79.3% (the
rate of 93.2% at the control), 21.5 – 73.8% (the rate of 90.6% at the control)
and 20.6 – 81.6% (the rate of 94.8% at the control), respectively. The survival
rate was the lowest of the plants derived from marked flowers and the highest
of the plants derived from marked pods. All seeds collected from marked
flowers at the dose of 20 Gy, and from marked flowers and pods at the dose
of 30 Gy had no survival.


13
b) Effect of gamma irradiation (60Co) on growth and development indicators of
soybean varieties irradiated on flowering plants
Gamma irradiation on flowering plants prolonged the growth duration
and reduced quantity traits such as stem height, a number of fertile pods,
individual yield....in soybean varieties. The higher the dose of gamma
irradiation was, the greater the effect of gamma irradiation on growth and
development was in M1 generation. There was little difference of growth and
development among treatments and the control in M2 generation.

c) Effect of gamma irradiation (60Co) on variation frequency and spectrum of
soybean varieties irradiated on flowering plants
Variation frequency of soybean varieties was on the increase with
the rise in gamma irradiation dose and reached at 100% from 30 Gy and over
doses. Variation frequency of soybean varieties DT2008, DT96 and ĐT26
ranged respectively from 31.5 – 100, 14.6 – 100 and 21.3 – 100% (the rate
of 0.0% at the control) in M1 generation, and from 30.1 – 100, 36.9 – 100 and
37.5 – 100% in M2 generation, and higher than the control (0 Gy).
200

200

100

100

0

0
0 (Đ/c)
DT2008

DT96

M1 generation

ĐT26

10

DT2008

20
DT96

30
ĐT26

M2 generation

Figure 3.3. Effect of gamma irradiation (60Co) on variation frequency of soybean
varieties irradiated on germination seeds in M1 and M2 generations

Gamma irradiation on flowering plants affected greatly on plant parts,
caused many morphological variations in M1 generation such as leaflet
variations (changed leaflet shape, blistered leaflet surface, enlarged or
elongated leaflet size, decreased number of leaflets), stem variations
(enlarged nodes, soft and slow-aging stem), pod variations (more than 2
valves, small pods). Especially, there were different variations on the same
plant. In M2 generation, there were 11 variations. A number of variations
were the most at the dose of 10 Gy (11 variations) and the lowest at the dose
of 30 Gy with only 2 variations of late maturation and sterileness (100%). At
the same time, significant variations for soybean breeding were selected such
as branchiness, short stem and fruitfulness at the doses of 10 and 20 Gy.


14
Table 3.25. Effect of gamma irradiation (60Co) on variation spectrum of
soybean varieties irradiated on flowering plants in M1 and M2 generations
Unit: number of variations

M1 generation
M2 generation
Radiation
doses
DT2008 DT96 ĐT26 DT2008 DT96 ĐT26
0Gy (control)
0
0
0
1
1
1
10Gy
2
2
2
11
11
11
20Gy
4
4
4
7
8
8
30Gy
4
4
4

2
2
2
40Gy
3
3
3
50Gy
3
3
3
60Gy
3
3
3
3.1.4. Evaluating the inheritance of morphological variations derived from
soybean varieties which were irradiated with gamma ray (60Co)
To evaluate the inheritance of morphological variations selected in M1
generation into M2 generation, variant individuals in M1 generation were
selected separately and sown in separate rows in M2 generation. In M1
generation, there were many morphological variations such as stem shape
(curved stem, flat stem, double stem), stem height (higher or shorter than the
origin), first branch (no branch, branchiness, branching at the cotyledon node,
symmetrically 2 branches at the same node, double branches), leaflet (leaflet
shape, number of leaflet…). However, all these variations didn’t inherited
into M2 generation. Therefore, these variations were modifications.
To evaluate the inheritance of morphological variations selected in M2
generation into M3 generation, variant individuals in M2 generation were
selected separately and sown in separate rows in M3 generation. In M2
generation, there were also morphological variations such as stem shape (flat

stem, double stem), first branch (branching at the cotyledon node,
symmetrically 2 branches at the same node, double branches…) and these
variations didn’t inherited into M3 generation either. Therefore, these
variations were modifications.
In addition, in M2 generation there were some new morphological
variations not found in M1 generation such as pubescence colour, pod coat
colour, seed coat colour, hilum colour. These variations were different to the
origins and inherited at the rate of 100% into M3 and M4 generations.
Therefore, these variations were genetic variations or mutants. The new
morphological variations which didn’t appear in M1 generation but come out
in M2 generation and inherited into M3 and M4 generations would be the


15
action of gamma causing changes in genetec structure, producing recessive
mutant alleles in M1 generation. In M2 and M3 generations, recessive
homozygotes appeared due to the self-pollination resulting in the appearance
of mutants. These mutants inherited completely into M3 and M4 generations.
The inheritance of these mutants could be explained as follows:
Table 3.26. The inheritance of morphological variations of soybean
varieties in M2, M3 and M4 generations
Ord.

1

2

3

Variations

Black
seed
coat
colour
(the origin’s
yellow)
Gray
pubescence
colour
(the
origin’s
brown)
Brown hilum
colour
(the
origin’s
black)

Number of
variant
individuals
in M2
3

The rate of
mutant
individuals
in M3
100%

The rate of
mutant
individuals
in M4
100%

ĐT26

3

100%

100%

DT96

1

100%

100%

ĐT26

1

100%

100%

ĐT26

1

100%

100%

Varieties
DT2008

Mutants of black seed coat colour were derived from DT2008 and
ĐT26 at the doses 200 and 150 Gy, respectively through irradiated on dry
seeds. Seed coat colour is a single gene characteristic controled by a gene
pair. In particular, green or yellow seed coat colour is dominant, black or
brown seed coat colour is recessive. So it can be assumed that yellow seed
coat colour controled by dominant allele Ri, black seed coat colour controled
by recessive allele ri. Black seed coat colour is controled by a pair of recessive
homozygous alleles riri, yellow seed coat colour is controled by pairs of
dominant alleles RiRi or heterogeneous alleles Riri.
Mutation
Self-polination Self-polination Self-polination
RiRi
Riri
ri ri
ri ri
ri ri
M0
M1
M2

M3
M4
(Yellow)
(Yellow)
(Black)
(Black)
(Black)

Mutants of gray pubescence colour were derived from the origins
DT96 and ĐT26 at the dose of 200 Gy and 10 Gy through gamma irradiation
on dry seeds and on flowering plants, respectively. Pubescence colour is


16
controled by a single gene pair. In particular, brown pubescence colour is
dominant and gray pubescence colour is recessive (Pham Thi Bao Chung,
2015). So it can be assumed that brown pubescence colour controled by
dominant allele Wpi, gray pubescence colour controled by recessive allele
wpi. Gray pubescence colour is controled by a pair of recessive homozygous
alleles wpiwpi. Brown pubescence colour is controled by pairs of dominant
alleles WpiWpi or heterogeneous alleles Wpiwpi.
WpiWpi
M0
(Brown)

Mutation
Self-polination Self-polination
Wpiwpi
wpiwpi
wpiwpi

M1
M2
M3
(Brown)
(Gray)
(Gray)

Self-polination
wpiwi
M4
(Gray)

Mutants of brown hilum colour derived from the origin ĐT26 at the
dose of 150 Gy through gamma irradiation on dry seeds. Black hilum colour
is dominant and brown hilum colour is recessive. Hilum colour in soybean is
controlled by 2 pairs of genes. The presence of dominant genes at the same
time will produce the interaction between them and create black hilum
colour. But the separate presence of two dominant genes will produce brown
hilum colour. So it can be assumed that black hilum colour controled by two
pairs of dominant alleles RtRtW1W1, brown hilum colour controled by pairs
of alleles RtrtW1W1, RtrtW1w1, rtrtW1W1, rtrtW1w1, rtrtw1w1.
* Mutagenesis at the first gene pair (Rt
rt):
Mutation
Self-polination Self-polination Self-polination
RtRtW1W1
RtrtW1W1
rtrtW1W1
rtrtW1W1
rtrtW1W1

M0
M1
M2
M3
M4
(Black)
(Black)
(Brown)
(Brown)
(Brown)

* Mutagenesis at the secondary gene pair (W1
Mutation
RtRtW1W1
M0
(Black)

w1):

Self-polination Self-polination Self-polination
RtRtW1w1
RtRtw1w1
RtRtw1w1
RtRtw1w1
M1
M2
M3
M4
(Black)
(Brown)

(Brown)
(Brown)

Therefore, induced mutation through gamma irradiation on soybean
varieties created many different variations. In particular, there were
variations that were modifications and not inherited to the next generation
such as stem shape (curved stem, flat stem, double stem), first branch (no
branch, branching at cotyledon node, symmetrically 2 branches at the same
node, double branches), leaflet (number of leaflets…). But there were
variations that were mutants and inherited to the next generation such as seed
coat colour, pubescence colour, hilum colour.
3.2. Research on selecting significant mutant soybean lines for soybean
breeding
3.2.1. Selecting mutant soybean lines significant for soybean breeding


17
The process of selecting mutant soybean lines was carried out
continuously from M2 to M7 generations based on observation and evaluation
of morphological characteristics, growth and development, resistance to
diseases… to identify mutant traits and select mutants significant for soybean
breeding.
a) Selecting mutant lines derived from the origin DT2008
Table 3.27. Number of mutant individuals or lines selected from treatments
of 60Co gamma irradiation on soybean variety DT2008
Unit: individual/line
Generations

M2
M3

M4
M5
M6
M7

Gamma irradiation on
dry seeds
150Gy
17
161
46
22
14
11

200Gy
31
392
136
69
51
46

250Gy
25
229
39
20
16
14

Gamma
irradiation on
germination
seeds
25Gy 50Gy
20
12
265
198
66
68
30
36
16
14
10
12

Gamma
irradiation on
flowering
plants
10Gy 20Gy
40
10
117
73
43
29

22
17
9
5
7
3

Total

155
1435
427
216
125
103

In M7 generation, 103 mutant lines were selected including 10 mutant
lines derived from treatments of gamma irradiation on flowering plants (7
lines at the dose of 10 Gy and 3 lines at the dose of 20 Gy), 22 mutant lines
derived from treatments of gamma irradiation on germination seeds (10 lines
at the dose of 25 Gy and 12 lines at the dose of 50 Gy) and 71 mutant lines
derived from treatments of gamma irradiation on dry seeds (11 lines at the
dose of 150 Gy, 46 lines at the dose of 200 Gy and 14 lines at the dose of 250
Gy). In particular, compared to the origin DT2008, there were 28 mutant lines
with 5.1 – 6.9cm higher stem height, 12 mutant lines with 1.2 – 1.8 more
branches, 26 mutant lines with higher yield, 19 mutant lines with 6 – 9 days
shorter growth duration and 18 mutant lines with black seed coat.
b) Selecting mutant lines derived from the origin DT96
In M7 generation, 58 mutant lines were selected including 9 mutant
lines derived from treatments of gamma irradiation on flowering plants (4

lines at the dose of 10 Gy and 5 lines at the dose of 20 Gy), 25 mutant lines
derived from treatments of gamma irradiation on germination seeds (16 lines
at the dose of 25 Gy and 9 lines at the dose of 50 Gy) and 24 mutant lines
derived from treatments of gamma irradiation on dry seeds (4 lines at the
dose of 150 Gy, 13 lines at the dose of 200 Gy and 7 lines at the dose of 250


18
Gy). In particular, compared to the origin DT96, there were 5 mutant lines
with straight growth habit, 4 mutant lines with 5 – 6.1 cm shorter stem height,
12 mutant lines with 1.2 – 1.8 more branches, 17 mutant lines with higher
yield, 4 mutant lines with 5 – 6 days shorter growth duration, 8 mutant lines
with gray pubescence and 5 mutant lines with different pod colour.
Talbe 3.29. Number of mutant individuals or lines selected from treatments
of 60Co gamma irradiation on soybean variety DT96
Unit: individual/line
Generations
M2
M3
M4
M5
M6
M7

Gamma irradiation on
dry seeds
150Gy
8
71
23

11
9
4

200Gy
23
246
54
33
17
13

250Gy
30
273
28
14
10
7

Gamma
irradiation on
germination
seeds
25Gy 50Gy
21
16
296
206
77

52
41
31
16
10
15
10

Gamma
irradiation on
flowering
plants
10Gy 20Gy
29
10
59
45
29
23
14
17
4
6
4
5

Total
137
1196
286

161
72
58

c) Selecting mutant lines derived from the origin ĐT26
Table 3.31. Number of mutant individuals or lines selected from treatments
of 60Co gamma irradiation on soybean variety ĐT26
Unit: individual/line
Generations
M2
M3
M4
M5
M6
M7

Gamma irradiation on
dry seeds
150Gy
5
148
114
52
35
35

200Gy
6
59
30

12
6
3

250Gy
6
51
23
12
7
7

Gamma
irradiation on
germination
seeds
25Gy 50Gy
17
8
223
131
52
37
27
23
13
4
12
1

Gamma
irradiation on
flowering
plants
10Gy 20Gy
42
10
81
89
29
22
18
15
10
5
10
5

Total
94
782
307
159
80
73

In M7, 73 mutant lines were selected including 15 mutant lines derived
from treatments of gamma irradiation on flowering plants (10 lines at the
dose of 10 Gy and 5 lines at the dose of 20 Gy), 13 mutant lines derived from
treatments of gamma irradiation on germination seeds (12 lines at the dose

of 25 Gy and 1 lines at the dose of 50 Gy) and 45 mutant lines derived from
treatments of gamma irradiation on dry seeds (35 lines at the dose of 150 Gy,
3 lines at the dose of 200 Gy and 7 lines at the dose of 250 Gy).


19
Therefore, nduced mutation through gamma irradiation on soybean
varieties DT2008, DT96 and ĐT26 created 234 mutant lines in M7 generation
including 103 mutant lines derived from the origin DT2008, 58 mutant lines
derived from the origin DT96 and 73 mutant lines derived from the origin
ĐT26. Mutant soybean lines have improved traits compared to the origins
such as shorter growth duration, higher yield, shorter stem height, black seed
coat….
3.2.2. Evaluating and comparing promising mutant soybean lines
To identify promising mutant soybean lines, promising mutant
soybean lines derived from DT2008 (8 lines), DT96 (6 lines) and ĐT26 (5
lines) were evaluated and compared in 3 crops of spring, summer and winter.
a) Evaluating and comparing promising mutant lines derived from soybean
variety DT2008
Table 3.35. The yield components and yield of promising mutant lines
derived from soybean variety DT2008 in Hanoi
Ord.
1
2
3
4
5
6
7
8

9
10

Lines/Varieties
08200-2/8
08200-25/24
08200-25/26
08200-9/1
08200-29/3
08200-26/11
08-2-25/4-10
08-6-25/3-8
DT2008 (đ/c 1)
DT84 (đ/c 2)
LSD0,05
CV(%)

Number of fertile
pods per plant
(pod)
S
A
W
44.3 62.7 30.2
43.5 62.9 30.8
44.9 61.8 28.7
45.1 63.2 29.2
45.3 62.8 29.7
45.7 63.4 29.5
44.7 65.2 30.8

45.3 64.8 31.4
45.3 64.5 30.4
24.3 37.8 19.6
3.54 6.39 3.71
4.8
6.1
5.5

Number of seeds
per pod (seed)
S
2.02
2.01
2.03
2.02
2.02
2.02
2.03
2.02
2.02
2.03
0.09
2.8

A
2.04
2.02
2.03
2.04
2.02

2.01
2.03
2.02
2.03
2.12
0.10
2.9

W
1.98
1.97
1.95
2.01
1.99
1.96
1.98
1.96
1.98
1.96
0.10
3.0

Real yield
(tons/ha)
S
2.84
2.87
2.79
2.84
2.87

3.00
2.76
2.77
3.03
1.89
0.15
3.1

A
3.12
3.08
2.95
2.96
2.88
3.18
2.91
2.83
3.34
2.68
0.16
3.0

W
2.44
2.56
2.35
2.46
2.38
2.46
2.41

2.34
2.68
1.82
0.13
3.2

S = Spring crop, A = Summer crop, W = Winter crop
Three promising mutant lines derived from the origin DT2008 were
selected including mutant line 08200-26/11 with black seed coat and shortest
growth duration, mutant line 08200-2/8 with 11.5 - 17.4 cm shorter stem
height compared to the origin DT2008, and mutant line 08200-25/24 with 7
– 8 days shorter growth duration compared to the origin DT2008. The line
08200-26/11, named as DT2008ĐT first and then DT215, was tested in the
value of cultivation and use in national testing and production trials.


20
b) Evaluating and comparing promising mutant lines derived from soybean
variety DT96
Three promising mutant lines derived from the origin DT96 were
selected including mutant line 96-2-25/1-10 with better lodging resistance
and straight growth habit, mutant line 96-6-25/5-3 with light brown pod coat,
and the most promising mutant line of 96200-13/2 with gray pubescence.
Table 3.39. The yield components and yield of promising mutant lines
derived from soybean variety DT96 in Hanoi
Ord.
1
2
3
4

5
6
7
8

Lines/Varieties
96-2-25/1-10
96-6-50/1-9
96-6-25/5-2
96-6-25/5-3
96200-13/1
96200-13/2
DT96 (đ/c 1)
DT84 (đ/c 2)
LSD0,05
CV(%)

Number of fertile
pods per plant
(pod)
S
A
W
30,3 41,8 27,8
29,7 40,8 26,3
29,7 40,2 26,5
31,3 42,5 28,6
29,3 38,9 27,2
28,3 38,5 27,4
29,7 40,6 27,5

24,8 36,5 20,4
2,86 4,86 2,19
5,7
6,9 4,7

Number of seeds
per pod (seed)
S
2,12
2,08
2,09
2,11
2,10
2,12
2,11
2,03
0,14
3,8

A
2,23
2,24
2,20
2,22
2,24
2,23
2,24
2,13
0,13
3,3

Real yield
(tons/ha)

W
2,05
2,04
2,06
2,03
2,05
2,04
2,04
1,95
0,11
3,1

S
2,69
2,58
2,56
2,77
2,44
2,62
2,52
1,96
0,12
2,7

A
2,91

2,89
2,85
3,01
2,86
2,98
2,94
2,35
0,16
3,2

W
2,42
2,38
2,31
2,45
2,30
2,47
2,42
1,91
0,14
3,2

S = Spring crop, A = Summer crop, W = Winter crop
c) Evaluating and comparing promising mutant lines derived from soybean
variety ĐT26
Table 3.43. The yield components and yield of promising mutant lines
derived from soybean variety ĐT26 in Hanoi
Ord.
26-2-25/2-6
26-4-25/3-10

26150-2/24
26150-1/3
26150-1/12
ĐT26 (đ/c 1)
DT84 (đ/c 2)
LSD0,05
CV (%)

Lines/Varieties
S
32,3
40,1
30,3
33,3
32,7
33,3
25,6

A
28,5
33,4
29,2
28,8
29,6
29,0
33,8

W
27,1
30,2

27,8
27,5
26,4
27,4
21,1

Number of fertile pods
per plant (pod)
S
A
W
2,48
2,42
2,61
2,52
2,43
2,62
2,50
2,41
2,58
2,49
2,40
2,61
2,51
2,43
2,60
2,51
2,42
2,60
2,02

2,10
1,96

Real yield (tons/ha)
S
2,24
2,56
2,17
2,36
2,26
2,38
1,92
0,14
3,4

A
2,04
2,36
1,97
2,18
2,05
2,14
2,26
0,19
5,0

W
2,23
2,48
2,10

2,26
2,13
2,25
1,88
0,18
4,6

S = Spring crop, A = Summer crop, W = Winter crop


21
Three promising mutant lines of 26-2-25/2-6, 26-4-25/3-10 and
26150-1/3 derived from the origin ĐT26 were selected. In particular, mutant
line 26-2-25/2-6 has shorter stem height and better lodging resistance with
the yield of 2.04 – 2.24 tons/ha equal to the origin ĐT26’s. Mutant line 264-25/3-10 has the yield of 2.36 – 2.56 tons/ha, 7-10% higher than the origin’s.
And mutant line 26150-1/3 has black seed coat with the equal growth and
development and yield compared to the origin ĐT26’s.
3.2.3. Evaluating the genetic diversity of some mutant soybean lines by SSR
markers

Figure 3.5. Diagram of genetic relationship between promising
mutant soybean lines and the origins.
The genetic diversity of promising mutant lines including 3 lines
derived from DT2008 (08200-26/11 named as DT2008ĐB, 08200-2/8,
08200-25/24), 3 lines derived from DT96 (96-2-25/1-10, 96-6-25/5-3,
96200-13/2 named as DT96ĐB), 3 lines derived from ĐT26 (26-2-25/2-6,
26-4-25/3-10, 26150-1/3 named as ĐT26ĐB), 1 line derived from DT2003
(2003-10n/8) and 4 origin varieties (DT2008, DT2003, DT96 and ĐT26)
were evaluated by SSR markers. The result showed that the genetic similarity
coefficient of mutant lines derived from the same ogirin was high and ranged

from 0.67 to 1.00, and higher than that of mutant lines derived from different
origin. The genetic similarity coefficient of mutant lines derived from
DT2008, DT96, ĐT26 was high and ranged 0.74 – 1.00, 0.78 – 1.00 and 0.64 –
0.88, respectively. In particular, the genetic similarity coefficient of mutant
lines DT2008ĐB and 08200-25/24, DT96ĐB and 96-2-25/1-10, 26150-1/3 and
26-2-25/2-6 was the highest. It was the lowest at mutant lines 26-2-25/2-6 and
26-4-25/3-10.
3.3. Testing the production trials of promising mutant soybean varieties
Promising mutant soybean varieties DT215 (DT2008ĐB), DT96ĐB
(96200-13/2) and ĐT26ĐB (26150-1/3) were tested in production trials in
Hanoi and Vinh Phuc.


22
3.3.1. Morphological characteristics
Mutant soybean variety DT215 has the same morphological
characteristics of purple flowers, brown pubescence, brown pod cover, black
hilum, pointed-egg shape leaflets, semi-straight growth habit and limited
growth type as the origin DT2008 but difference from seed coat colour.
DT215 has black seed coat different from DT2008’s yellow seed coat.
Mutant soybean variety DT96ĐB has the same morphological
characteristics of purple flowers, medium brown pod cover, yellow seed coat,
gray hilum, pointed-egg shape leaflets, semi-straight growth habit and
limited growth type but difference from the colour of hair of main stem.
DT96ĐB has gray pubescence different from DT96’s brown pubescence.
Mutant soybean variety ĐT26ĐB has the same morphological
characteristics of white flowers, brown pubescence, dark brown pod cover,
black hilum, semi-straight growth habit and limited growth type but
difference from seed coat colour. ĐT26ĐB has black seed coat different from
ĐT26’s yellow seed coat.

3.3.2. Growth and development traits
Promising mutant soybean varieties have higher growth and
development but longer growth duration compared to soybean variety DT84
(check). The growth duration of varieties DT215, DT96ĐB and ĐT26ĐB
ranged from 90 – 100, 90 – 94 and 86 – 91 days, compared to the growth
duration of the origins DT2008, DT96, ĐT26 and the check DT84 of 95 –
100, 89 – 95, 87 – 91 and 83 – 88 days, respectively.
The range of the growth duration of the origins DT2008, DT96, ĐT26
and the check DT84 was 95 – 100, 89 – 95, 87 – 91 and 83 – 88 days,
respectively.
The stem height of promising mutant soybean varieties was higher
than DT84’s and the highest in summer crop. The stem height of DT215,
DT96ĐB and ĐT26ĐB ranged from 61.5 – 70.8, 52.1 – 59.8 and 41.8 – 51.6
cm, respectively, compared to the stem height of the origins DT2008, DT96,
ĐT26 and the check DT84 of 62.4 – 71.1, 50.6 – 58.2, 41.5 – 53.2 and 35.5
– 47.0 cm.
3.3.3. Resistance
The resistance of promising mutant soybean varieties is higher than or
equal to the origins’ but higher than the check DT84’s. They have mild
infection of rust (score 1) and powder mildew (score 1-2), and good lodging
resistance (score 1-2).
3.3.4. Yield components and yield
Mutant soybean variety DT215 had the real yield similar to DT2008’s
but higher than the check DT84’s. In Hanoi, DT215 had the real yield of 2.71
– 3.32 tons/ha (38.8 – 51.4% higher than the check DT84), DT2008 had the
real yield of 2.65 – 3.35 tons/ha. In Vinh Phuc, DT215 had the real yield of
2.72 – 3.31 tons/ha (32.6 – 51.1% higher than the check DT84), DT2008 had
the real yield of 2.75 – 3.92 tons/ha.

23
Mutant soybean variety DT96ĐB had the real yield similar to DT96’s
but higher than the check DT84’s. In Hanoi, DT96ĐB had the real yield of
2.22 – 3.06 tons/ha (20.6 – 29.1% higher than the check DT84), DT96’s had
the real yield of 2.26 – 2.95 tons/ha. In Vinh Phuc, DT96ĐB had the real
yield of 2.46 – 2.88 tons/ha (19 – 38% higher than the check DT84), DT96’s
had the real yield of 2.58 – 2.78 tons/ha.
Table 3.51. The real yield of promising mutant soybean varieties
Unit: tons/ha
Varieties
DT215
DT2008 (origin)
DT96ĐB
DT96 (origin)
ĐT26ĐB
ĐT26 (origin)
DT84 (check)
LSD0,05
CV%

Spring
2.81
2.84
2.58
2.65
2.48
2.52
1.98
0.19
4.2

Hanoi
Summer
3.32
3.35
3.06
2.95
2.35
2.26
2.37
0.22
4.5

Winter
2.71
2.65
2.22
2.26
2.23
2.32
1.79
0.20
4.9

Spring
2.87
2.92
2.65
2.72
2.55

2.65
1.92
0.17
3.7

Vinh Phuc
Summer Winter
3.21
2.72
3.24
2.75
2.88
2.46
2.78
2.58
2.38
2.28
2.42
2.20
2.42
1.80
0.24
0.23
4.9
5.3

Mutant soybean variety ĐT26ĐB had the real yield similar to ĐT26’s
but higher than the check DT84’s. The real yield of ĐT26ĐB ranged 2.23 –
2.48 tons/ha in Hanoi (ĐT26’s yield of 2.26 – 2.52 tons/ha) and 2.28 – 2.55
tons/ha in Vinh Phuc (ĐT26’s yield of 2.22 – 2.65 tons/ha), 15.9 – 32.8 and

24.6 – 28.6% higher in spring and summer, respectively, compared to the
check DT84.
Among three promising mutant soybean varieties, black soybean
variety DT215 with yield potential and good resistance was tested in national
testing VCU in 2018-2019. The result showed that variety DT215 had good
growth and development, high stem, branchiness, mild infection of rust,
downy mildew, brown spots (score 1-3), good lodging resistance (score 1-2)
and non-splitting pods (score 1) with the average yield of 2.32 – 2.56 tons/ha,
9.9 – 28.4% higher than DT84’s. Variety DT215 was recognized as a selfdeclared circulation variety under the notice No. 654/TB-TT-CLT dated June
8, 2020 of Department of Crop Production, Ministry of Agriculture and Rural
Development.
3.3.5. Nutritional content
Promising mutant soybean varieties have high nutritional content
and equal to the origins’ with the protein content of over 40% (DT215,
DT96ĐB and ĐT26ĐB have the protein content of 42.26, 40.10 and 40.50%,
respectively), lipid content of over 18% (DT215, DT96ĐB and ĐT26ĐB
have the lipid content of 18.24, 18.09 and 21.65%, respectively), glucid over
25% (DT215, DT96ĐB and ĐT26ĐB have the glucid content of 25.13, 26.50
and 25.59%, respectively). Therefore, these varieties can be used as materials
to produce soymilk, tofu…