Mutation Breeding of Rice for the Sustainable Agriculture in Vietnam
Le Huy Ham, Vo Thi Minh Tuyen, Nguyen Thi Hong
Agriculture Genetics Institute, Vietnam
Introduction
In Vietnam, rice plays an important role for national food security and politicalstability. Rice also has a direct effect on social security because it is consumed by nearly
89 million of the total population and an important source of income for more than 90
million people living in agricultural and rural areas. Rice is the country’s main crop,
accounting for more than 90% of total cereal productivity. Rice production in 2015
reached 45 million tons, and it is 0.3% higher than in 2014. Vietnam is one of the top 5
countries that studies reveal will be severely impacted by climate change. A rise in sea
level of 1 meter will inundate about 5,000 square kilometers (km2) of the Red River Delta
and 15,000–20,000km2 of the Mekong River Delta, reducing total rice production in
Vietnam by about 5 million tons. Bad harvests, natural calamities, floods, and pests anddiseases will also occur more often. Ensuring domestic food security has thus become anational objective that requires long-term strategies and policies, especially for theprotection of the agricultural land area. Vietnam does not only seek to achieve domestic
food security but it also plays an important role in the international rice market, andconsequently, in the food security of the international community.
Despite of a decrease in rice land area, rice production has been rising due to rapid
yield growth. This in turn has been driven by irrigation and land development, together
with technological change. In 2009, Vietnam had nearly 7.4 million hectares (ha) of ricelands, which declined to 2 million ha in 2015 (Ministry of Agriculture and Rural
Development, 2015). However, rice productivity increased from 39,5 million tons in 2009
to more than 45 million tons in 2015. This was a remarkable achievement due to theapplication of advanced science and technology such as the introduction of different rice
varieties, new production models, and an efficient irrigation system. Post harvest losses
have also been reduced greatly due to the mechanization of rice harvesting and drying,and soil improvement.
Mutation Breeding in Vietnam
At present, about 15% of rice production area is covered annually by mutant
89varieties in Vietnam. Great achievement by the use of nuclear techniques and related
biotechniques. More than 55 mutant varieties were developed, in which most of varieties
are cereal crops, especially rice.
The used materials were local lines (Cuom, Chiem bau, Tam thom, Nang thom, Nang
huong, Te etc.) and the varieties presently used in the crop productivity (C4-63, A8,
CR203, Khang dan, IR64, IR50404, Bac thom). The treatment methods were dry seeds
with different radiation doses (Gamma ray, X-ray with 80, 100, 150, 200, 250 Gy, usefuldoses were 100, 120, 200 Gy); the others were germinated seeds with radiation doses of20, 30, 40, 80 Gy, useful doses were 30, 40, 60 Gy).
Since the 1990s, the Agricultural Genetics Institute (AGI), Vietnam Academy ofAgricultural Sciences (VAAS), has been engaged in R&D activities and contributed muchto the technology transfer to the agricultural sector of Vietnam. Mutation breeding is oneof the major fields of institute in crop improvement, in which the biggest
accomplishments have been achieved in the development of mutation varieties for crops
production. Before 2000, objective of mutation breeding is often quantity of yield variety.
One very interesting example from AGI is DT10 mutant variety which has been certified
as national variety in 1990 due to the high performance, good tolerant to harmful
condition. This variety is available in rice more than 25 years and now this is still
disseminating in some specific location. This variety covers the area around 1.0 mil. ha
in agriculture production. After success of mutant variety DT10, scientists from AGI
released series of mutant varieties (20 mutant varieties) and satisfied production
demand.
In the South Vietnam, mutation induction has been carried out mostly in Cuulong
Rice Research Institute and Institute of Agriculture South Science (IASS). These
institutions have also succeeded in the mutation breeding by the use of nuclear
techniques. Over the past decade, the institutes have developed eight excellent mutant
varieties with high yielding, improved quality, disease resistance, tolerance to pest andlodging resistance. One of these excellent mutant varieties (VND9s-20) which has beencertified as national variety in 1999 became one of the top five varieties for riceproduction. It covered 300 thousand ha per year in south of Vietnam, due to its highyielding, good quality and tolerance to brown plant hopper. Not only has this variety
been widely cultivated in the low lands, but also expanded to the high lands and remotemountain areas, where poor farmers are benefiting from growing it.
The great support from the Vietnamese Government makes the application of
nuclear techniques in food and agriculture so successful. Due to the excellent
performance of the mutant rice varieties mentioned above, some of these mutant
90

varieties were adopted for the national strategy program of “Eradicate hunger andalleviate poverty” in different areas, particularly for central highland region, where there
are many ethnic minorities living in remote mountain areas. Most of the eight mutant
varieties have shown out-standing performance under local production conditions.
Release of new mutant rice for large scales of production
Recently, beside of yield varieties, scientists has been concentrating creation of newvariety having good performance on quality (aroma, protein, amylose content, componentof quality), as well as tolerance to harmful condition of environment such as salinity, coldor high temperature, drought, lodging variety and so on. Mutation breeding is powerfultool for rice breeding improvement.
During 2008 - 2017, groups of rice breeders continue effective collaborations for pureline selections under field trials of rice mutants and their crossings with high quality
and tolerance in Red River Delta (North Vietnam) and Mekong River Delta (South
Vietnam). There are ten outstanding new varieties have been certified as new varieties
and ongoing projects to enlarge mutation varieties in different provinces (Table 1).
Khang dan mutant variety has been transferred the trading rightcopyright from
AGI to the seed company since 2008 after it was certified as national variety. With someadvantages, the area covered with this variety is around 300 thousands ha/year in northVietnam. In 2012, the seed company is rewarded the national prize for Khang dan
mutant variety due to the leading area for agriculture production of this variety.
ĐB5, ĐB6 mutant varieties have high yield, good tolerant to pest and disease. OM
2496 has high productivity, aroma and salinity tolerance. Nam dinh 5 variety has Quality,
aroma and high yield. PD2 is glutinous rice and photo sensitiveness. It has high yield
and aroma. P6 mutant has short growth duration (85-90 days in summer season) andhigh temperature tolerant. Mutant rice varieties DT39 Quelam, CNC11 have improvedin productivity for high yield, better quality and tolerant to bacterial leaf blight.
Moreover, DT39 gave high nutrition content such as iron, zinc, Kali and Maggie incomparison to origin variety.
Mutant rice varieties DT39 Quelam and CNC11 has been transferred the trading
rightcopyright from AGI to the seed company.

91

Table 1. Leading mutant varieties in rice production in Vietnam (duration 2008-2015).
No
1

Variety

Year ofcertify

Dominant characters

Area ofproduction/year (ha)Khangdan

2008

High yield, good tolerant to pest and disease

300,000

ĐB5

2008

High yield, good tolerant to pest and disease

5,000

ĐB6

2008

High yield, good tolerant to pest and disease

5,000

OM 24962009

High productivity, Aroma, Salinity tolerance

3000

PD2

2010

Glutinous rice, photo sensitiveness, high

10,000mutant2
3
4
5

yield, aroma
6P6 mutant

2011

Short growth duration 85-90 days in summer

15,000season, high temperature tolerant7

Nam dinh 52012

Quality, aroma, high yield

3,500

8

ĐB15

2012

High yield, good tolerant to pest and disease

600

9DT39 Que2013

Quality, high protein, high yield, resistant to800

leaf blight

lam
10

CNC11

2015

Quality, high protein, high yield, resistant to300

leaf blight

Applications of gamma rays irradiation and marker assisted selection for improving ofrice varieties for the sustainable agriculture.
Climate change creates adverse conditions for rice production in rice growing
regions. For adaptation to mentioned challenges, cultivation of varieties resistant tobiotic and abiotic stresses is required.
In present, the application of irradiated techniques and biotechnology in rice
breeding has focused on some major traits, such as high yield, short duration, goodquality, bacterial leaf blight resistance, blast resistance and salt tolerance.
92

In 2013, dry seeds of three varieties were irradiated with 300 grey of Cobalt-60
gamma rays. Among them, BT62.1 was resistant to bacterial leaf blight (carrying Xa7,

Xa21 genes), P5.3 was resistant to blast (carrying Piz gene), and BT3.1 was salt tolerantvariety (carrying saltol gene). All of these varieties have low yielding. Purpose ofirradiation is improvement of yield. M1 and M2 plants of these varieties were evaluatedfor mutant characteristics. We expect to get the mutant lines not only have resistance todiseases but also have high yield, short duration, and good quality.
In 2014, M3 and M4 progenies of these varieties were used for marker assisted
selection (MAS) and inoculation in the green house to select elite lines resistant tobacterial leaf blight resistance, blast resistance and salt tolerance. Twenty M4 mutant
lines (from M4.1 to M4.20) retained as short duration, good quality, bacterial leaf blightresistance, blast resistance or salt tolerance as original varieties but they have thehigher yield than the original ones.
In 2015, these lines are evaluated the agronomic and biological traits as well as
resistance characters in field condition (narrow scale). The results showed that: 6
promising mutant lines were selected (2 mutant lines showed high resistance to the BB
pathogen, 2 lines resisted the BL pathogen and 2 lines showed high salt tolerance in thefield. The promising mutant line, DT80 carrying saltol gene and can withstand salinityof 0,6%. DT80 was evaluated in salinity field of the Nam Dinh province in spring season2015.
In 2016, DT80 mutant line was evaluated the agronomic and biological traits as wellas tolerant characters in field condition (narrow scale) and send the National testing
Center. Beside of this activity, promising lines should be evaluated in different local
conditions for evaluation of wide adaptability of new variety and evaluate the responseof the farmer. The result of this evaluation indicated that DT80 mutant variety have
improved in productivity for high yield (Potential yield: 6,8 - 7 ton/ha), better quality(amyloze contents: 14%), short growth duration (105-110 days in summer season),medium plant height (112 cm), Wide adaptation and easily cultivation. This new mutant
variety were evaluated with some major pests and disease and the evaluation in the fieldshowed that DT80 were affected by these biotic and abiotic stresses in the majority ofharmful levels from 1-3 points.
DT80 was sent to The National Testing Center for Crops to test for Value ofCultivation and Use of crop (VCU) 3 seasons and Distinctness, Uniformity and Stabilityof crop (DUS) 2 seasons.
DT80 mutant variety has been transferred the trading right from AGI to the Thanh
hoa seed company in November, 2016. In 2017 it registered as new variety by MARD.
93

Results of irradiation ion beam on rice breeding
Carbon ion beam have been recently considered as potential mutagens. A
characteristic feature of ion beams is their ability to deposit high energy on a target,
densely and locally. Rice seeds were treated with Carbon ion radiation (40, 60, 80 and
100 Gy) by AVF-Cyclotron at the Japan Atomic Energy Research Institute (JAERI),
Takasaki, Japan and were planted and selected at the Agricultural Genetics Institute.
There are some results of carbon ion Beam irradiation up to now.

Table 2. Overview irradiation data.
Varieties

Time

Dose

Bac thom and Khang dan

6/201040Gy and 60Gy

CMBT and BLBT

3/201340Gy and 60Gy

DT80, DT82, DT86, T5, TBR2 and RVT6 1/2015

60Gy and 80Gy

BC/6 and P12

6/2015

40Gy, 60Gy, 80Gy and 100Gy

ĐB2, KN6, BH96/2016

40Gy, 60Gy, 80Gy and 100Gy

Results of carbon ion beam irradiation on Bac thom and Khang dan
There are many types of variations in M2 generation from irradiated Bacthom andKhang dan. Four promising mutants were selected from Khang dan in which two lines
came from dose of 40Gy and two other mutant lines were derived from dose 60 Gy. Mostof the mutant lines express higher yield than the original variety and better resistant topests and diseases. However, the objective of the project is to increase yield and to obtain
good quality rice variety, therefore the research is concentrated in Bacthom variety.
Selection process was conducted according to better agronomic traits; short growduration, high yield and purity of mutant lines in the M4 and M5 generations. The
mutant lines were grown and evaluated similar to the M5 and M6 but in the expanded
testing area and perform in some different locations to assess purity, growth anddevelopment capacity, as well as yield and resistance to pests and diseases. The
promising lines will be chosen for further research. Result indicated in the table 1 and 2
below. In M7 generation of Bacthom mutant variety showed that grow duration of somemutant lines (M7-2, M7-6 and M7-8) were similar to control; meanwhile some mutant
line indicated short grow duration than the origin such as M7-4; M7-3. In M7 population,
purity of 3 mutant lines M7-3, M7-4 and M7-5 were in level 1 better than the origin inlevel 5 as well as M7-2, M7-6 and M7-8. However, purity level of mutant line can be94

improved by selection process in further generation. Panicle length is also one ofcomponent of yield performance of variety. Most of mutant lines have panicle length thatis longer than the control of Bacthom variety. That mean of most mutant lines may havehigher yield compare to original Bacthom variety.
Table 3. Biological and agricultural characteristics of 6 Bacthom mutant lines in M7(summer season 2013).
Lines

GrowthPlant

Flowering

Plant

PaniclePuritydurationheightduration

hardnesslength(points)

(day)

(cm)

(points)(points)(cm)

BT (Cont.)

107

108.0

5

3

21.5

5

M7-2

107

115.6

5

3

25.8

5

M7-3

104

114.4

5

1

23.6

1

M7-4

102

117.2

5

3

24.5

1

M7-5

105

108.2

5

1

22.1

1

M7-6

106

109.6

5

3

22.4

5

M7-8

108

102.8

5

3

24.2

5

•

Plant hardness: 1-Very hard,

3-Hard, 5-Medium hard,

7-Weak hard,

9-

Weak hard.
•

Flowering duration: 1-Focus (≤ 3 days), 5-Medium (4-7 days), 7-Long (≥7 days)•

Purity: 1-High (different trait ratio <0,25%), 5-Medium (different trait ratio:

0,25-1%), 9-Low (different trait ratio > 1%).
With regards to the grain yield component of mutant lines in the M7 generation
showed a significant difference compare with the control for full seed per panicle thehighest were obtained at M7-4 and M7-8 lines and showed significant difference fromother lines (table 2). This resulting in potential yield of M7-4 and M7-8 were higher thanthat of original and other lines with 9.63 tons/ha and 12.48 tons/ha. These other mutant
lines performed grain yield higher than original variety except M7-6 which was 5.34
ton/ha. However, one elite mutant to be selected will not only depend on the yield
performance character but also on the cooking quality and aroma characteristic of thevariety.

95

Table 4. The grain yield components of 6 mutant lines of mutant Bacthom in M7(Summer season 2013).
No. ofLinespanicle/hill

No. of seeds

No. of full

Weight ofPotential

seed

1000 seeds

yield/panicle(gr)(ton/ha)/panicle

BT (Cont.)

5.1

140.5

130.9

19.6

5.50

M7-2

5.3

177.6

159.3

22.1

7.84

M7-3

5.2

182.2

160.4

19.8

6.94

M7-4

5.8

212.4

197.7

20.0

9.63

M7-5

6.0

132.7

119.3

19.5

5.86

M7-6

5.5

127.3

118.5

19.5

5.34

M7-8

6.2

257.9

236.1

20.3

12.48

Cooking quality is main objective of the breeding improvement. Six mutant lines of
Bacthom were tested in room condition for aroma, softness, stickiness, and taste toevaluate the quality of selected mutant lines in comparison to original variety.. The
result of this experiment indicated that M7-2; M7-3; M7-6 and M7-8 have cooking
qualities similar to the original variety Bacthom, meanwhile M7-4 and M7-8 indicateddry and hard when cooked even M7-4 and M7-8 but have highest grain yield.
Results of carbon ion beam irradiation on CMBT and BLBTIon beam irradiation 3/2013: The variable new mutant lines were screened andevaluated in M2 generation. (selected lines with short growing period, medium plantheight, tillering ability, a number of seeds per panicle is higher than that of variety
control. Specially, selected lines reveals small tillering angle, this is characteristic need
to be improved from original lines). Selection process was conducted according to better
agronomic traits; short grow duration, high yield and purity of mutant lines in the M3
and M4 generations.
Screening of mutant lines in M5 and M6 generation. In this period, agrobiologicalcharacteristics and tolerance traits is being tested in the field conditions (narrow scale).
MAS was applied to identify the target genes. The prospective lines in M5 generation to
be continued in varietal testing system for assessment of the agro -biologicalcharacteristics: field grain yield and grain quality towards approval as national varieties.
Five mutant lines (two from CMBT, three from BLBT) with high potential yield and goodagronomic traits were selected96Based on agronomic traits in fields, test in greenhouse and MAS in lab, 14 promisingmutant lines in M5 generation were selected: 5 mutant lines from CMBT and 9 mutant
lines from BLBT.
The results showed that 4 promissing lines (BL.1,2,6,7) have a growth duration isshorter and number of fulled seed is much higher than that of control. So that these lines
obtained the higher yield than control variety (Table 9).
The results showed that 2 promissing lines (CM.3,4) have a growth duration isshorter and number of fulled seed is much higher than that of control. So that these lines
obtained the higher yield (7.5 ton/ha) than control variety (Table 5).
In 2015 spring season, the total of 6 promissing mutant lines were obtained. Theseline will be selected in 2016 for evaluating the agronomic traits and resistance to pests
and diseases.
Table 5. Agronomic traits and yield potential of BB mutant lines in M5 from BLBT
(Spring season, 2015).
No

Mutantlines

Durationof growth(days)Height ofplant (cm)Number of

PanicleNumberpanicle/exertion of fulled

plant

(cm)

seed

Weightof 1000
grains(gr)

Potential
yield(ton/ha)

Cont.

BLBT

130

109

6.5

2.3

184.7

22.3

5.7

1

BL.1

129

95

8.0

3.0

219.0

19.8

6.9

2

BL.2

128

95

8.0

3.2

236.7

20.1

7.2

3

BL.3

132

95

5.0

4.2

167.7

19.5

6.5

4

BL.4

130

95

7.0

3.0

192.3

20.2

5.9

5

BL.5

127

100

7.0

0.8

180.0

21.2

5.6

6

BL.6

125

100

7.0

1.7

257.7

21.5

7.5

7

BL.7

130

105

6.5

0.6

276.9

21.0

7.1

8

BL.8

129

100

5.8

0.9

242.0

21.4

6.1

9

BL.9

125

102

6.0

0.5

261.3

21.4

6.4

97

Table 6. Agronomic traits and grain yield components of Salinity tolerance mutant
lines in M5 from CMBT (Spring season, 2015).

No

Mutantlines

Duration Height of Number ofPanicleNumberof growthplant

panicle/exertion of fulled(days)

(cm)

plant

(cm)

seed

Weight of1000
grains(gr)

Potential
yeild(ton/ha)

Cont.

CMBT

128

111

6.0

2.5

159.5

22.2

5.5

1

CM.1

128

105

8.0

3.5

183.0

20.3

5.9

2

CM.2

130

105

8.0

1.3

183.3

20.1

6.4

3

CM.3

129

100

8.0

-0.5

248.0

20.8

7.5

4

CM.4

130

100

8.0

-0.7

251.0

20.5

7.1

5

CM.5

129

100

7.0

5.7

145.3

21.3

6.7

Table 7. Agronomic traits and grain yield components of promising mutant lines(summer season, 2016).
No

Mutantlines

Durationof growth(days)Height ofplant (cm)Number of

PanicleNumberpanicle/exertion of fulled

plant

(cm)

seed

Weightof 1000
grains(gr)

Potential
yeild(ton/ha)

Cont.

BLBT

105

110

5.5

2.3

145.7

22.5

5.3

1

BL.1

102

98

5.8

3.0

179.0

20.0

6.5

2

BL.2

108

100

6.1

3.2

186.7

20.1

6.8

6

BL.6

105

102

6.8

2.7

217.5

21.3

7.5

7

BL.7

103

110

6.5

0.3

176.9

21.0

6.1

3

CM.3

107

108

7.0

0

178.0

20.5

6.5

4

CM.4

105

109

6.5

0.2

175.0

20.6

6.1

Cont.

CMBT

128

109

6.0

2.5

159.5

22.0

5.5

98

The results of evaluating the agronomic trait in the field (Table 11) showed thatthese lines have a shorter duration, with higher production in comparison with control.
Three mutant lines: BL7, CM.3, CM.4 were high yield, but their panicle exertion is very
short (0-0.3cm). This reason make these lines can increase higher empty seed ratio for
reducing the yield. Out of which, the promissing BL6 line revealed hard stem hardness,
can resistance with abiotic and biotic stresses. Next, these lines will be adapted indifferent rice ecosystem to production expanding and sent to The National Testing
Center for Crops to test for Value of Cultivation and Use of crop.
Table 8. Summary results of carbon ion beam irradiation (From 1/2015).

Variety

DT80

DT82

DT86

T5

TBR2

RVT6
Total

M4

M5

(mutant(Promissing

lines)

line)

25

5

0

25

37

8

0

89%

10

15

12

8

80Gy

91%

20

18

5

0

60Gy

91%

26

20

8

0

80Gy

91%

30

18

9

4

100Gy

95%

18

24

9

6

60Gy

87%

9

16

12

7

80Gy

88%

15

21

5

0

60Gy

87%

29

32

9

0

80Gy

88%

5

0

0

0

60Gy

85%

31

25

5

3

80Gy

92%

45

18

6

3

278

269

93

31

Dose

M1

M2

M3

Sterility

variation

variation

60Gy

83%

15

80Gy

86%

60Gy

99

Results of carbon ion beam irradiation from 2015 to 2017
The variable new mutant lines were screened and evaluated from M2 to M5
generation. We selected lines with short growing period, medium plant height, tillering
ability, a number of seeds per panicle is higher than that of variety control. The resultsin table 7 showed that: 278 mutant individual in M2 generation were selected in 2015.
In 2016, 269 mutant individual in M3 generation and 93 mutant lines in M4 generation
were selected. In 2017, based on agronomic traits in fields, 31 promising mutant lines in
M5 generation were selected: 18 promising lines from 60 Gy, 7 promising lines from 80
Gy and 6 lines at 100 Gy.
In 2016, 56 mutant individual in M2 generation were selected with short growing
period, medium plant height, tillering ability, a number of seeds per panicle is higher
than that of variety control. In 2017, Set of 102 mutant lines were obtained in M3
generation, 39 mutant lines in M4 generation were selected. The results showed that
(Table 8): 17 mutant lines were selected from 60 Gy, 7 mutant lines from 80 Gy and 15
mutant lines at 100 Gy.
Table 9. Summary results of carbon ion beam irradiation (From 6/2015).
Time
irradiation

Variety

6/2015
BC/6

P12

M4

Dose

M1

M2

M3

Sterility

variation

variation

40Gy

75%

0

0

0

60Gy

91%

15

26

17

80Gy

91%

5

12

0

100Gy

95%

3

9

0

40Gy

68%

5

0

0

60Gy

91%

12

18

0

80Gy

91%

10

23

7

100Gy

95%

6

14

15

56

102

39

Total

100

(mutant
lines)

Table 10. Summary results of carbon ion beam irradiation (From 6/2016).
Variety

BH9

KN6

ĐB2

Dose

Germination*

M1

M2

Sterility

variation

40Gy

100%

75%

60Gy

100%

91%

31

80Gy

99%

91%

23

100Gy

97%

95%

14

40Gy

100%

65%

60Gy

98%

91%

11

80Gy

100%

91%

22

100Gy

100%

95%

24

60Gy

100%

91%

80Gy

91%

100Gy

95%

20

From irradiated time 6/2016: 145 mutant individual in M2 generation were selected
in 2017. Among that: 44 mutant lines were selected from 60Gy, 45 mutant lines from
80Gy and 58 mutant lines from 100Gy.
The promising mutant line with some improved traits such as: light aroma, softer
endosperm, good tillering ability, big and longer seed size, more grain number per
panicle....comparing to original variety. Thus, our research was focused on database of 5
target genes regulated these features as in table below:
Through sequence and BLASTN, total of 24 point mutants were identified in target
genes (as in table).

101

Table 11. Results of study to clarify mutation related to high yield and good quality
Material of study.
No.
1

Name

Features

Original variety (DT82)

BLB resistance, low yield, tillering ability (4-5
tillers), plant height (113-115cm), dark green
leaf, small seed, dark yellow husk seed2

Ppromising line (60Gy)

BLB resistance, improved yield, better tillering(8-10 tillers), plant height (120 cm), light green
leaf, better quality, big and long seed, lightyellow husk seed

Table 12. Target gene information.
No.
1
2

Gene name
Os08g0424500
Os06g0133000

Regulation
BetaineGene features
aldehyde

Chr.8(21703754:21707360),

dehydrogenase, Rice fragrance

including 13 exons

Glutinous endosperm

Chr.6(1929936:1935488),

including 15 exons
3
4

5Os03g0171600
Os07g0261200

Os03g0203200

Leaf senescence, seed size andChr.3(4284298:4286750)

grain number

including 1 exon

Grain number, plant height, andChr.7 (9173610:91755560)

heading date 7

including 2 exons

Shoot branching

Chr.3(5895977:5897579),

including 2 exons102

Table 13. Identified point mutations in target genes.
Gene

Number of mutant

Os08g0424500
Os06g0133000

6

Location of mutants
Exon 1 (40, 41, 42, 47, 48); exon 12 (121)
Exon 3 (33, 34, 35, 70); exon 4 (15); exon 9

6

(115)

Os03g0171600

5426, 615, 621, 1017, 1263

Os07g0261200

4Exon 1 (73, 253); exon 2 (32, 36)

Os03g0203200

3

Exon 2 (24, 98, 401)

Total

24

Conclusion-

The dose of 60 Gy is effective for screening good trait mutants-

To be need further trial to assess the efficiency of dose 80Gy and 100Gy-

Mutations conducted from ion beam were almost point mutations

Work plan- Testing promising lines in different ecological zones- Continue screening mutation lines to select the good and stable lines- Repeat the irradiation with range of doses to performed the most effective dose formutation breeding.

Conclusion
Successful story of mutation plant breeding in Vietnam is contributed from politicalsupport by Vietnamese government for mutation plant breeding research such as
international organization such as FAO/IAEA, through project IAEA/VIE/05/13/14 from1997-2003 and Ministry of science and Technology Foundation was supported by
Program: Applied research and development of energy technologies; code: KC05.09/1115 from 2012-2015. Beside of this from 2008, Vietnam became official member of Forumfor Nuclear Cooperation in Asia (FNCA). Scientists from different institutions havechance to go abroad and attend training course, scientific symposium and workshop, or
to exchange information and experiences with scientists working in mutation breeding.
It’s clear that mutation induction nowadays is one of powerful tool for crops improvement103

in Vietnam. Mutant rice varieties from institutions contribute to increase of riceperformance and productivity in recent years. This is confirmed that Vietnam
Government has been concentrating research and development of the activities on
nuclear techniques in agriculture. Beside of that farmers also benefit from scientificresearch activities.

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