MINISTRY OF EDUCATION AND
TRAINING
CAN THO
UNIVERSITY
SUMMARY OF DOCTORAL THESIS
Specialization: Biotechnology
Code
: 62 42 02
01
DAO THI TUYET THANH
INDUCING OF MUTATION TUBEROSE
(Polianthes tuberosa L.) LINES BY IRRADIATING
WITH 60Co GAMMA RAYS IN VITRO
Can Tho,
2018
THIS STUDY WAS COMPLETED AT
CAN THO UNIVERSITY
Scientific supervisor:
Assoc. Prof. Doctor NGUYEN BAO TOAN
The dissertation was defended at the university examination
committee
At.………………………………………., Can Tho University
At……….. hour ….…, on date……..month…..…. year……
Referee 1:
Referee 2:
Referee 3:
The dissertation is available at Libraries:
1. Central library of Can Tho University.
2. National library of Vietnam.
PUBLISHED PAPERS
1. Nguyen Bao Toan, Nguyen Quang Thuc and Dao Thi Tuyet
Thanh, 2014. 60Co Gamma treatment at different irradiated doses on shoot
clusters of two (Polianthes tuberosa) varieties in vitro. Can Tho University
Journal of Science. (4): 41 - 46 (in Vietnamese).
2. Dao Thi Tuyet Thanh and Nguyen Bao Toan, 2016. Effects of
60Co gamma doses on the growth and development of in vitro tuberose
shoot clusters (Polianthes tuberosa L.), appearance of abnormal structures
and LD50 determination. Can Tho University Journal of Science. Part B:
Agriculture, Aquaculture and Biotechnology. 45: 25 - 32 (in Vietnamese).
3. Dao Thi Tuyet Thanh, Le Thi Ngoc Quy and Nguyen Bao Toan,
2017. Study on growth and flower diversity of single petal tuberose clones
(Polianthes tuberosa L.) irradiated with 60Co gamma rays by tissue culture.
Journal of Vietnam Agricultural Science and Technology. 2(75): 47 - 52 (in
Vietnamese).
4. Dao Thi Tuyet Thanh and Nguyen Bao Toan, 2017. Study on
genetic diversity of tissue cultured tuberose lines (Polianthes tuberosa L.)
irradiating with Co60 by using ISSR marker. Journal of Vietnam
Agricultural Science and Technology. 6(79): 20 - 24 (in Vietnamese).
5. Dao Thi Tuyet Thanh and Nguyen Bao Toan. Effects of gamma
radiation doses on the growth, flowering and phenotypes of tuberose
(Polianthes tuberosa L.) lines propagated by tissue culture. Journal of
Biotechnology. (Accepted, in Vietnamese).
1
Chapter I: INTRODUCTION
1. Necessity of the dissertation
Polianthes tuberosa L. is one of the most popular cut flowers in the
tropics and subtropics. In Vietnam, it helps farmers get more income than
rice and other crops do. Thus, it has been included in the crop restructuring
program and considered a poverty reduction crop in the provinces: Tien
Giang, Dong Thap, Can Tho and An Giang. Nowadays, there are only two
varieties of tuberoses with 6 petals and 12 petals which are mainly
cultivated in the Mekong Delta.
However, the propagation of tuberose is mainly rooted through
generations leading to serious degeneration, pest infestation and significant
reduction in productivity. Therefore, the demand for new varieties is
exigent. In addition, breeding of tuberose in the traditional way has
encountered some limitations due to high incompatibility because the
flowers have stigmas and stamens which are not ripe at the same time and
this is the reason why their seeds are not created under natural conditions
(Estrada-Basaldua et al., 2011). Moreover, only the single petal flowers can
produce seeds, but it is difficul for the seeds to sprout. Perhaps, the mutation
is the best way to breed a new tuberose variety. Among physical mutagenic
agents, gamma rays are most widely used because of their effectiveness
(Matsumara et al., 2010). This technique increases genetic variation in some
type of flowers such as changes in color, shape, growth characteristics, etc
(Xu et al., 2012). Furthermore, in vitro culture should be applied to increase
the number of irradiated samples. Propagation of tuberose in vitro has been
experimented (Huynh Thi Hue Trang et al., 2007; Hutchinson et al., 2004).
Whereas, growth culture and irradiation are the effective methods to make
plants uncontaminated, multiply rapidly and mutate. This combination is
successfully applied on palms, apples, potatoes, sweet potatoes and
2
pineapples (Ulukapi and Nasircilar, 2015) and can be selected properly to
produce tuberose varieties.
On the other hand, petals play an important role in flowering,
pollination and cross-fertilization… For ornamental plants, the number of
petals is related to the flower pattern. When in vitro culture is combined
with gamma ray treatment, changes to the number of rose and daisy petals
have been reported (Usenbaevard and Imankulova, 1974; Kahrizi et al.,
2012; Nagatomi, 2001). Thus, it is possible for tuberose to induce new
source of variations in the characteristics of large numbers of petals by in
vitro and gamma ray processing. Until now, in Vietnam, there have not been
any new tuberose variety with many petals created by traditional methods as
well as by other modern biotechnological techniques. For these reasons, it is
necessary to carry out the study on "Inducing of mutation tuberose
(Polianthes tuberosa L.) lines by irradiating with 60Co gamma rays in vitro"
2. Research objectives
2.1. General objective: To get mutant flowering flowers that have
more number of petals than the study samples, larger flowers and more
aromatic.
2.2. Specific objectives: (1) To evaluate growth culture technique to
generate calli and shoots for irradiation of gamma ray; (2) To identify lethal
dose of 50% (LD50) of gamma rays (60Co) on callus and rhizomes of
tuberosa after 150 days; (3) To observe the phenotypic abnormalities of the
domesticated stage; (4) To choose 1 to 2 mutant tuberose lines that increase
the number of petals (more than 12 petals) with large size and fragrant
odour by traditional breeding methods.
3. Research subjects and scope of the study
- Two tuberose varieties including of the single and double petal
flower are being cultivated in An Giang province.
- Investigating mutant line characteristics in the field over 2
generations.