MINISTRY OF EDUCATION
AND TRAINING
MINISTRY OF AGRICULTURE
AND RURAL DEVELOPMENT
VIETNAM ACADEMY OF AGRICULTURAL SCIENCES
DONG THI KIM CUC “Research and application of molecule
markers in breeding salt-tolerant Bacthom 7
rice variety”
Major: Genetics and Breeding

Objection1:
Objection2:
Objection3:
The Doctoral thesis is defelded at Institute Committee of PhD
Dissertation Examination:
VIETNAM ACADEMY OF AGRICULTURAL SCIENCES
At……day…….month ………… 2014
PhD thesis can be found at:
- Nationa Library of VietNam.
- Library of VietNam Academy of Agricultural Sciences 1

INTRODUCTION
1. Imperativeness of the thesis
Rice production and yield are significantly losses due to diseases and pests infestation and the
environmental impacts. Of these, the noticeable factor is salt-influenced to rice. The cultivated lands
have been affected from the salinity by 380 million ha, accounted for 1/3 total worldwide cultivated
areas.
Salt – affected lands is the main factor which has curbed to develop productivity of rice, and also

2

Based on the successful archivements of application of marker assisted backcrossing to transfer
salinity tolerance QTL into other rice varieties will be widely applied for rice breeding to cope with
climate change in the foreseeable future.
Application of molecular breeding to combine with the traditional breeding to accelerate and identify
the salinity tolerance rice materials, to pyramid it into Bac Thom 7 which could help to overcome the
constrains of traditional breeding, especially with the heterzygote salinity tolerance QTL, reducing
the cost of experiments, shortening the time and rapidly applying in practice.
3.2. Practical Significance
The success of Saltol transfering into Bac Thom 7 based on molecular breeding will be widely
applied for rice molecular breeding.
The improved Saltol salinity tolerance of Bac Thom 7 lines would be selected and grown in a
larger scale, especially for the coastal areas in the north of Viet Nam, where the most adversed
influence from the climate change are.
The most other significance of the current thesis was to simultaneously develop the salinity
tolerance line/variety with the highest genetic background of the Bac Thom 7 and carried the Saltol
QTL. The newly improved lines would grow well in the salt areas.
4. Plant materials and the Scope study of thesis
4.1. Plant materials to study
The inbred rice varieties carrying the salinity tolerance (Saltol) which were imported from the
IRRI, and the inbred rice varieties are popularly grown in Vietnam, as well as using the related
molecular markers in the current study.
4.2. Places and time to conduct experiments
The experiments were carried out at the Molecular Biology Division, Agricultural Genetics
Institute, (Tu Liem, Hanoi); and the Center of Technological Exchange and Extension (Thanh Tri,
Hanoi), and Giao Thuy, Nam Dinh Province.
4

CHAPTER I
OVERVIEW AND SCIENTIFIC BACKGROUND

• Phenomenom of salt prevention • Phenomenom of leaf to leaf patition
• Phenomenom of re-absorbance • Tolerance ability by the tissues 5

• Moving from root to bud •Dillution influence
1.3.2. Genetics of Salinity tolerance
1.3.2.1. Reseach on genetics of quantitative traits of salinity tolerance
According to Mishra et al (1998), the trait of salinity tolerance in plant is polygenic trait,
negligible causing effect from the parental plant (recipient plant) because these genes are not located
in the cytoplasm [72]. During development stage of rice, the plant height, and rice production under
salt affection are controlled by the additative genes (Mishra et al 1990)[73].
1.3.2.2. Research on salinity tolerance at molecular level
Based on the QTL mapping, salinity tolerance is controlled by multi-genes. Some markers such
as AFLP and STS have been used, the major gene has been identified and located on the chromosome
1 and named as Saltol. The QTL (quantitative trait loci) mapping has been applied in case of the
target gen has been controlled by many genes (example as salinity tolerance trait)
1.3.3. Expression of salinity tolerance of gene
Based on the morphological, physiological and biochemical characteristics of the experiment, we
have observed the present of Saltol-rice varieties and the sensitive rice varieties (without Saltol)
1.4. Molecular markers and their application
1.4.1. Molecular marker
Molecular markers (or DNA markers) are polymorphic markers. They are included the

1.4.4. Application of Marker assisted backcrossing (MABC)
MABCis an a practical and efficient technique in transferring the interested QTL/gene into the elite rice
variety to generate the improved rice variety in a short time carrying the desire QTL/gene and attain
approximately 100% genetic background of the elite rice variety: The breeding programe may only
implement at the BC3 or even thought in BC2 generation, respectively.
1.5. Some archievements in improving rice salinity tolerance
1.5.1. Some results and archivements in research on rice salinity tolerance in the world
During the year 1977 to 1980, International Rice Research Institute (IRRI), was successfully
selected the good rice salinity tolerance such as IR42, IR4432-28-5, IR4595-4-1, IR463-22-2, and
IR9884-54-3 with the yield at 3,6 tones/ha. Gregorio et al (2002)[45] developed TCCP226-2-49-B-B-
3 rice cultivar with high salinity tolerance ability.
Some local rice varieties which were derived in the East Asia have often been high salinity tolerance
such as Nona Bokra (India), Pokkali (Sri Lanka), Getu (India), SR26B, Damodar, Cheriviruppu, Pat
and Solla (India), Ketumbar (Indonesia), Khao Seetha (Thailand). Some rice varieties were in the
template (subtropical countries) such as Harra (Spanish), Agami (Egypt), and Daeyabyeo (Korea).
Several Japonica rice varieties such as Moroberekan have high salinity tolerance, which were
origined in the affected salt areas. This variety has been researched and used as the donor plant
(salinity tolerance) and population mapping (Kim et al, 2009)[55]. The rice varieties were Oryza
glaberrima, which are mostly grown in the West African show lower salinity tolerance ability to
compare with the rice varieties (Oryza sativa) (Awala và cs, 2010)[2].
Recently, in 2013, researchers in IRRI have successfully developed the high-super salt
tolerance that could be very useful for the farmers to grow this rice cultivar in the affected salt areas
such as the coastal areas.
1.5.2. Application of molecular markers in improving salinity tolerance of rice
The fine mapping of Saltol QTL was made on the chromosome 1 by the researcher groups
(Gregorio 1997; Bonille et al 2002; and Niones 2004) which explained about 40-65% salinity


Phong/1548 during the year of 2001-2005. 8

CHAPTER III
MATERIALS, CONTENTS AND METHODS
2.1. Materials
The rice materials included:
 Total 14 rice lines/varieties carrying Saltol QTL salinity tolerance were imported from
IRRI and some popularly grown rice varieties in Red River Delta
 Chemical argents and research facilities:
SSR markers used: 447 markers
Research instruments: Experimental tools of Agricultural Genetics Institute
2.2. Areas to conduct experiments
The Laboratory of Molecular Biology Division-Agricultural Genetics Insititute. Tuliem-Hanoi
The Net house and paddy fields conducted for experiment at the Center of Technology
Exchange and Extension, Vinh Quynh, Thanh Tri, Hanoi