MINISTRY OF EDUCATION AND TRAINING - MINISTRY OF AGRICULTURAL AND RURAL DEVELOPMENT VIETNAMESE ACADEMY OF FOREST SCIENCES LA ÁNH DƯƠNGĐOÀN NGMAIỌC DAO RESEARCH ON GENETIC VARIATION AND
Trang 1MINISTRY OF EDUCATION AND TRAINING - MINISTRY OF AGRICULTURAL AND RURAL DEVELOPMENT
VIETNAMESE ACADEMY OF FOREST SCIENCES
LA ÁNH DƯƠNGĐOÀN NGMAIỌC DAO
RESEARCH ON GENETIC VARIATION AND HEREDITARY ABILITY IN GROWTH AND HEART ROT IN SECOND-
GENERATION PROGENY TEST OF Acacia mangium
DOCTOR OF PHYLOSOPHY IN FORESTRY
THESIS SUMMARY
Trang 2The thesis has been completed in Vietnamese Academy of Forest
Science
Supevisor: 1 Ass.Prof Dr Nguyen Hoang Nghia
2 Dr Phi Hong Hai
Chair of PhD thesis defense Committee:
Trang 41 Problem statement
Acacia mangium has been planted in Vietnam since early of 1960s (Le Dinh Kha,
Nguyen Hoang Nghia, 1991) Acacia mangium seedling improvement program was started from 1980s As a result of this program, many origin species of Acacia
mangium such as Pongaki, Cardwell, Iron Range, SW Cairns and Bloomfield have
been recognized as technical progress seedling source and applied in practice In theprogram, the research results about variation and heritability of the first generationtrials which carried out in Hanoi showed that the heritability for growth varies fromlow to moderate, while it fluctuations from medium to high for cellulose content,collapse rate, wood density, modulus of elasticity, modulus of rupture and woodshrinkage rate From this result, the preeminent families in first generation trials wereselected, collected and used to develop second-generation progeny test in 2008-2009
period (Ha Huy Thinh et al., 2011) By the end of 2016, there have been 14 varieties
of Acacia mangium recognized by the Ministry of Agriculture and Rural
Development (MARD), thereby greatly contributing to improving the productivityand quality of plantation production forests in Vietnam
The plantation in large-scale monoculture cause to strongly development of
disease, typically Heart rot which are common in Acacia mangium Diseases caused
by some fungal species which reduce the quality of wood, affect the pulp properties,reduce wood recovery and mechanical and physical properties of wood The factorscausing Heart rot diseases can be limited by breeding and appropriate silvicultural
measures (Lee, 2002; Rimbawanto, 2006) However, research about Acacia mangium
varieties improvement before 2012 only focused on assessing the variation andhereditary ability in growth, stem quality and quality of wood chip and sawn timber
of first generation progeny test The study of Heart rot disease is very limited andonly assessed the variation of decay between different origins Therefore, it isnecessary to study the genetic variation related to Heart rot disease at the family level
Trang 5at different age levels, thereby selecting varieties that are resistant to disease orability to recover well after the plants become infected by diseases
Based on about reasons and inheriting the field trial setup in research project
"Research on improvement of varieties in order to increase wood quality and yieldfor some common forest plantation species" and the project "Development of woodtree varieties for economic plantation in the period of 2006-2010", the thesis"research on genetic variation and hereditary ability in growth and Heart rot in second-
generation progeny test of Acacia mangium” has been carried out with the aim of contributing to scientific background to guide strategies for improving Acacia
mangium variety in Vietnam.
2 Scientific and practical significance of the thesis
+ Selected a number of Acacia mangium families from second-generation progeny
test with some characteristic such as fast growth, high wood quality, low level Heartrot
3 Research object
+ Research goal
Identifying the genetic variation and hereditary ability characteristics of someimportant traits that serve as a scientific basis to contribute to further study about
Trang 6Acacia mangium seedling improvement toward high yield and ability to resist decay
disease
+ Specific object
- Identifying the genetic variation characteristics of some traits related to growth,wood quality and decay disease
- Identifying method for evaluating Heart rot disease by ArborSocnic 3D device
- Identifying hereditary ability, genetic gain related to Acacia mangium breeding
selection
- Identifying the relationship between growth, wood quality, mechanical andphysical properties of wood traits and Heart rot disease
4 New contribution of the thesis
- The first time in Vietnam, the method of indirect evaluation Heart rot disease
by ArborSonic 3D device with high precision for Acacia mangium has been applied.
- Having a comprehensive assessment the level of genetic variation, hereditary
ability of decay disease and growth, wood quality traits on A mangium in Vietnam
5 Research subject
The subjects of the study are the A mangium families which selected from different
seed sources in the second generation progeny test The testing models were setup in2008-2009 period
6 Scope of research
(1) The dissertation only conducted research on the degree of variation and
genetic ability in Acacia mangium families in the second generation posterior trial at
different ages in Hanoi, Nghe An and Binh Duong
(2) The study identifies the method of assessing decay disease by new method ofusing ArborSonic 3D device, comparing with the methods which are widely used,
carried out on 30 A mangium trees in 9 year old which were planted in Doan Hung
Trang 7-Phu Tho Then, this method was tested on 120 trees of 40 families (3 trees/family)and compared with the method of assessing decay level of Caroline (2006) in thesecond generation progeny test in Bau Bang
(3) Due to the high budget consume of mechanical and physical wood propertiestest, and must be destructive trees in the trial, the research about correlation betweendecay level and mechanical and physical wood properties was only conducted in 120trees (3 trees/family) of 40 families in the second generation posterior trial in BauBang
(4) Researches on identifying fungal pathogens and affecting of site conditions
on Heart rot diseases have been carried out, however, scope of this research is aboutbreeding, these research results related to fungal pathogens and affecting of siteconditions on Heart rot disease are not presented in this thesis
7 Thesis structure
Introduction: 6 pages
Chapter 1: Literature review: 32 pages
Chapter 2: Content and research method: 18 pages
Chapter 3: Result and discussion: 53 pages
Chapter 4: Conclusion, limitation and recommendation: 3 pages
Trang 8Chapter 1 LITERATURE REVIEW 1.1 Over the world
Acacia mangium is native species of Australia, Papua New Guinea and Indonesia.
The species is fast growing and adaptable on a variety of site conditions Acacia
mangium therefore plays an important role in reforestation and plantation programs.
Many researches on this species have been conducted in many countries such asresearching on biological characteristics, selecting varieties, planting techniques aswell as usability
In the 1990-2000 period, studies by Awang and Taylor (1993); Susumu andRimbawanto (2004); Harwood and Williams (1991); Turvey (1996); and Nirsatmanto
et al (2003) was often focused on finding high-yielding provenances
In the 2000-2010 period, studies of genetic variation at the family level of A.
mangium had shown that genetic variation from low to moderate for growth traits and
stem quality and target average value for wood density trait The hereditarycorrelation between growth and wood density is positive (Nirsatmanto and Kurinobu,2002; Arnold and Cuevas, 2003; Susumu and Rimbawanto, 2004; Nirsatmanto et al.,2004; Kim et al., 2008; Khasa et al., 1995) There are many successful story related
to tree breeding (Walker and Haines, 1998; Darus, 1993; Gerad et al., 1999; Griffin etal., 2010)
Research about disease has also been focused In recent time, diseasemanagement has always been one of the main goals of variety improvement research
programs (Mayank et al., 2012) Research about diseases on acacia species has also been introduced in Ken Old et al (2000) Decay disease is a common disease in
tropical acacia species and has been the subject of research by many authors, such as
Lee et al (1988); Lee and Maziah (1993); Mahmud et al (1993); Ito and Nanis (1997); Mehrotra et al (1996) The level of decay disease can be very high in Acacia
Trang 9mangium plantation, ranging from 50-98% (Zakaria et al., 1994); Ito and Nanis,
1994; Basak, 1997)
Decay disease in Acacia mangium is caused by a typical fungus of Basidiomycetes
class (Hood, 2006), which breaks down both cellulose and lignin, eventually
changing the color of wood to yellow-white, porous or fibrous (Caroline et al., 2006).
They usually occur in older trees, but sometimes in 2-year-old trees (Lee, 2002),especially in large-scale plantations (Mahmud, 1993) Fungal pathogens might
infiltrate to Acacia mangium via wounds caused by stem canker diseases, or from damaged stems, pruned branches and broken branches (Mahmud et al., 1993; Ito and Nanis, 1994, 1997; Barry et al., 2004) Signs or symptoms of this disease usually
don't show to the outside of trees
Research related to disease-resistance breeding have been carried out for many
forestry species in the world and achieved positive results Zakaria et al (1994) demonstrated that in A mangium, the higher the diameter, the greater the incidence of
decay disease
1.2 In Vietnam
The Acacia mangium variety improvement in Vietnam has been conducted since
the 1980s In the 1990s, provenance trials were setup synchronously andsystematically The results show that the genetic variation among the origin of
Acacia is quite large (Le Dinh Kha and Nguyen Hoang Nghia, 1991); Mai Dinh Hong
et al., 1996; Le Dinh Kha, 2003) Prospective sources are Pongaki (PNG), Oriomo
(PNG) and Bimadebun (PNG), Deri - Deri (PNG), Cardwell and Pascoe (Qld),Ingham (Qld) and Mossman (Qld)
Based on promising origins, provenances test/first generation test in combining
with the establishment of Acacia mangium seed orchards in Hanoi and Binh Phuoc in
1996-1998 (Le Dinh Kha, 2003) Results showed that there are significantly differentbetween stem volume, growth and wood quality among families Heritability for
Trang 10growth traits range from 0.12 to 0.33 and vary according to age Heritability of wood
mechanical and physical properties of Acacia mangium is high, ranges from 0.21 to
0.38 for cellulose content, collapse rate, density, modulus of elasticity, modulus ofrupture and wood shrinkage rate However, heritability cumulative of relatively low
at only about 1.6-9.5% Relationship between growth traits is a strong correlationbetween ages of 3, 5, 9, and 11 Heritability correlation between growth traits andwood quality, the author noted that diameter is strongly correlated with modulus ofrupture and cellulose content (Doan Ngoc Dao, 2012)
In the second-generation progeny test of A mangium, the assessment of genetic
variation at 3-4 years old showed that there are significantly different between
diameter, height, stem volume, wood quality among families (Phi Hong Hai et al.,
2015) Heritability of the growth traits are low to moderate (h2 = 0.04-0.30).However, hereditary cumulative covariance of most traits exceeded 5-7%
Genetic gain in theoretical for growth and stem straightness is 8.8% to 23.4%.Research on the genetic correlation between growth traits and wood quality (PhiHong Hai et al., 2015) shows that improvement in growth parameters will have apositive effect, but not significantly on stem straightness and wood density, and maynot strongly affect to modulus of elasticity, stiffness and wood shrinkage rate
Studies about A mangium propagation in Vietnam have been conducted in many
different ways such as marcotting, grafting, cuttings and tissue culture (Le Dinh Kha,
1992; Ha Huy Thinh et al., 2010; Phi Hong Hai et al., 2015).
Research about disease on Acacia also have been carried out A recent study
estimated the incidence of this disease in A mangium, A auriculiformis and A ranges from 7.1 to 12.5%; 9.2 - 18.4% and 10.2 - 18.2% respectively (Pham Quang Thu et al., 2016) Research related to characteristics of Acacia mangium, Acacia
auriculiformis, Acacia hybrid in Dong Ha - Quang Tri showed that Acacia mangium
at the age of 7 years has the percentage of hollow trees accounting for 40% (NguyenTrong Nhan, 2003) Research by Le Dinh Kha and Doan Ngoc Dao (2011) onassessing the incidence of decay contents for 39 lowland acacia species, including 9
Trang 11different provenance Acacia at 17 years of age in Da Chong – Hanoi, the result showed that the incidence of Acacia mangium is very high, from 50.8-96.6%.
There is a difference about decay rate between provenances of Acacia mangium.
The study results also indicated there is not relationship between tree growth and the
decay incidence rate, not follow any rule Both A mangium origin of fast growth and
the slow growth have low rate and high rate of of heart rot
1.3 Insight from literature review
The research results have identified suitable growing conditions for Acacia
mangium as well as many achievements in seedling improvement However, the
quality of wood is not high due to the use of low quality varieties that was not
improved or improved at a low level (provenance) Wood from A mangium
plantation still has many disadvantage such as high rate of shrinkage after drying,high rate of wood death knots, Heart rot, etc Some new varieties have recognised bycharacteristics of fast growth, trunk quality, mechanical and physical properties ofwood However, the indicators for varieties recognized are not relate to disease
resistance, including Heart rot diseases that are very common in Acacia mangium.
Research on Heart rot disease is still limited and only assessing the level of Heartrot among provenances The study about decay disease should focus on determiningthe level of decay disease at all ages group of tree; the relationship between the level
of decay disease and the seedling sources and family as well as the impact of theenvironment on decay disease
Trang 12Chapter 2 CONTENT, MATERIAL AND RESEARCH METHOLOGY
2.1 Research content
1) Research about level of genetic variation related to growth, trunk quality and
Heart rot diseases on A mangium in second-generation progeny test.
2) Evaluating level of Heart rot by applying ArborSonic 3D device;
3) Identifying heritability, the relationship between different traits; understandingthe effect of interactions between genotypic context and living environmental on
straits such as growth traits, stem quality and Heart rot diseases on Acacia mangium;
4) Estimate the genetic gain of growth traits, stem quality, and Heart rot disease
in second-generation progeny test of A mangium
5) Selecting a number of Acacia mangium families with high productivity and
resistant to Heart rot disease
2.2 Research object
A Mangium varieties group includes 253 families from 16 provenances in
second-generation progeny test in Hanoi, Nghe An, Binh Duong and 30 averageAcacia trees (age of 9 years) from plantation production forests in Doan Hung - PhuTho
2.3 Research method
2.3.1 Heart rot evaluation method
+ Heart rot incidence rate (%): automatically measured by ArborSonic 3D;measurement by percentage of diseased area/basal areas of tree at breast height ofindividual tree
Trang 13+ The level of Heart rot (Di-3D): measured and simulated by ArborSonic 3Ddevice; the device will calculate based on the porosity of wood and the differentcolors of the entire 3D section at breast height of trunk Through actual inspection oftrunk cross section, based on color and incidence of decay measured by Carolinemethod (2006) as wel as result from ArborSonic 3D measurement, author divided thelevel of Heart rot in to 5 level, from 0 point to 4 point in order to assess the incidence
of diseases on each individual Acacia mangium tree in second-generation progenytest (Figure 2.1)
- -
-Figure 2.1: The level of Heart rot from 0 - 4 points (in above image, the picture onthe left is a wood cross section,; the picture on the right is the ArborSonic 3D device
4 point
Trang 14Selecting 30 average Acacia mangium trees at 9 year old from production forest
in Doan Hung - Phu Tho Before felling trees, the assessment of decay level byArborSonic 3D is done on a standing tree Then the trees were cut and take out 30pieces of wood (1 cross section piece/tree) at breast height Samples of wood cuttingcross section were smoothed, took photographs and then assessed the level of decayaccording to the method of Caroline (2006) and TCVN 8928: 2013 On images ofwood cutting cross section, the actual rate of Heart rot was determined by usingMapinfor software to measure the ratio of areas of diseased parts to the basal area of the cutting wood cross section
- Assessment of decay level by Caroline’s method (2006) (Di): Level of decay
was ranks from 0-4, the higher the score, the greater the level of decay
2.3.2 Tree growth and trunk quality data collection method
Growth parameters such as diameter at breast height (D1,3), height (H) and heightbelow branches (Hdc) were measured for all trees in the trial; Stem straightness (Dtt),branch size (Dnc): is group according to 5 levels (scale from 1 to 5 points) according
to Vietnam standard 8761: 2017
2.3.3 Methods of determining the physical and mechanical properties of wood
- Determining wood density by applying water displaced method (Olesen, 1971)
- Sampling and determining mechanical and physical properties were carried outaccording to Vietnamese standards (TCVN 8044: 2009)
2.3.4 Data analysis
Data was analysised according to method suggested by Williams et al (2002).
Some common statistic softwares were used such DATAPLUS 3.0 and Genstat 12.0(VSN International), SAS 8.0 (SAS Institute, 2002) and ASREML 4.0 (VSNInternational)