MINISTRY OF EDUCATION AND TRAINING MINISTRY OF AGRICULTURAL AND RURAL DEVELOPMENT VIETNAMESE ACADEMIY OF FOREST SCIENCES NGUYEN HUU SY GENETIC VARIATION AND HEREDITARY ABILITY IN
Trang 1MINISTRY OF EDUCATION
AND TRAINING
MINISTRY OF AGRICULTURAL AND RURAL DEVELOPMENT VIETNAMESE ACADEMIY OF FOREST SCIENCES
NGUYEN HUU SY
GENETIC VARIATION AND HEREDITARY ABILITY IN
GROWTH AND WOOD PROPERTIES OF Eucalyptus urophylla S.T
Blake AND ITS HYBRIDS WITH OTHER EUCALYPTUS SPECIES
Major: Forest genetic and tree breeding
Code : 9620207
DOCTOR OF PHYLOSOPHY IN FORESTRY THESIS SUMMARY
Hanoi - 2020
Trang 2INTRODUCTION
1 Introduction
Eucalyptus urophylla S.T Blake, a fast-growing tree species, naturally
distributed in Indonesia and East Timor It adapted to many types of soils such
as bare hills, poor-nutrient terrain Therefore, it has been planted in many
countries around the world In Vietnam, Eucalyptus urophylla has been widely
grown in the Central North, North Central and Central Highlands to provide raw materials for pulp production, sawlog and ply wood (Le Dinh Kha, 2004)
The E.urophylla breeding program was started in the 1990s of the last century
with the establishment of species and provenance trials Some good provenances such as Lewotobi Flores, Egon Flores for the Central North, and Lembata Flores have been selected for the North Central region (Nguyen Duong Tai, 1994; Le Dinh Kha, 2004)
In the period 2000 - 2005, progeny trial of first-generation in conjunction with
the establishment of Eucalyptus urophylla seedling seed orchard was conducted
by the Research Centre for Forest Tree Improvement (now the Institute of Forest Tree Improvement and Biotechnology) The second-generation progeny trials have been continued within the framework of a long-term and continuous
improvement program for E urophylla has been planted However, the breeding program for E urophylla mainly focused on growth traits and for raw
timber purpose In the meantime, the second generation progeny trials only assessed growth to the age of 6, researches on wood properties only focused on wood density and cellulose content Therefore, it is necessary to study the genetic variation in growth after the age of 6 and some wood properties, which
are directly related to the use of E urophylla as sawn timber (wood shrinkage,
wood cracks)
During 2012-2104, some hybrid combinations between E urophylla and other Eucalyptus species were planted in Ba Vi - Hanoi, Dong Ha - Quang Tri and
Trang 3Bau Bang - Binh Duong Some UP hybrids (E urophylla x E pellita) clones
selected by the Institute of Forest Tree Improvement and Biotechnology have yielded up to 25-35m3/ha/year on degraded, poor-nutrient terrains in Ba Vi, Hanoi and Dong Ha, Quang Tri (Ha Huy Thinh et al., 2015; Mai Trung Kien,
2014) However, UG hybrids (E urophylla x E grandis), a potential hybrid has
not been studied intensively, otherwise, the hybrid breeding trials between
Eucalyptus urophylla and other species only accessed the growth data to the
post-3-year-period, so continuing to monitor their growth after 3 years as well
as studying some wood properties are necessary for a complete assessment of
the development capacity of Eucalyptus hybrid varieties for sawlog purpose
In the framework of the results of the project “Breeding high yield and quality varieties for some common forest plantation species" in the 2001-2005 period,
the project "Breeding new hybrid clone between Eucalyptus pellita and other varieties of Eucalyptus" in the period 2011-2015, project “Development of
improved wood varieties for economic plantation" in the period of 2006 - 2010
has developed second-generation progeny trials and hybrid groups between E urophylla and other species of Eucalyptus To further evaluate the research direction of E urophylla and their hybrids with other Eucalypts with the aims
of contributing to the guide strategy for varieties improving to increase productivity and high quality for sawn timber purposes, thesis "Genetic
variation and hereditary ability in growth and wood properties of Eucalyptus urophylla S.T Blake and its hybrids with other Eucalyptus species" were
conducted
2 The scientific and practical significance of the thesis
- Scientific significance
The dissertation results have added scientific foundations on the breeding
Eucalyptus variety and their hybrid with other Eucalyptus varieties: E pellita,
Trang 4E grandis, E camaldunensis…in the direction of improving productivity and
quality of sawn timber planted forests
- Practical significance
+ Selected 05 families, 05 hybrid combinations and 92 good individuals
of Eucalyptus urophylla and Eucalyptus hybrids based on growth ability and
properties assessment
+ Selected 03 mother trees capable of creating good hybrid combinations
as the basis for hybrid breeding
3 Research objectives
- Theoretical objectives
Identifying the genetic variation and hereditary ability characteristics of growth,
wood properties and genotypic interactions of Eucalyptus urophylla in
second-generation progeny trials
- Practical objectives
Identifying several fast-growing individuals of Eucalyptus urophylla and
Eucalyptus hybrid which is also good trunk quality as the foundation on selecting varieties for sawn timber plantation
4 New contribution of the thesis
- This is the first study on growth traits associated with wood properties
(wood density, wood shrinkage) for E urophylla in the second-generation orchard and hybrid combinations of E urophylla and other Eucalyptus
varieties
- This is the first study in details about log-end splitting in E urophylla in second-generation progeny trials opens a research direction in breeding E urophylla and Eucalyptus hybrid in the future
5 Research materials
The subjects of the study are the E urophylla families which selected from
different seed sources in the second generation progeny trials which established
Trang 5in the period 2005-2007 and hybrid combinations were created in the hybridization trials in 2012-2014 period
6 Scope of research
- The dissertation only conducted investigate variations in some growth traits (diameter at breast height, total height, and trunk volume) in second generation progeny trials (periods of 10 and 15 years at Ba Vi, 8 and 13 years in Nam Dan) Some wood properties (density, shrinkage, splitting) at the age of 8 years in the second generation progeny trial at Nam Dan
- The study has scope in understanding growth variability at 3, 4, 5 and 8 years in hybridization trial in 2012 at Ba Vi, Dong Ha and Bau Bang and some wood properties (density, modulus of elasticity) at 3 and 6 years in hybridization trial at Ba Vi in 2014
7 Thesis structure
Introduction: 6 pages
Chapter 1: Literature review: 33 pages
Chapter 2: Objectives, materials and methods: 20 pages
Chapter 3: Results and discussions: 88 pages
Chapter 4: Conclusions, limitation and recommendation: 4 pages
Trang 6Chapter 1 LITERATURE REVIEW 1.1 In the world
Eucalyptus urophylla is a large timber species belonging to Myrtaceae family, which is classified to sub-genus Symphyomyrtur (Wilcox, 1997; Pryor & Johnson, 1971) In the world, E urophylla was found in Indonesia and East
Timor The tree can reach a height of 25-45 m, sometimes this figure can reach over 55 m, the diameter can reach from 1-2 m (Turnbull and Brooker, 1978) They can crossbreed with other Eucalyptus varieties easily to create hybrid clones with high vitality under natural conditions through open pollination (Brooker and Kleinig, 2012)
A lot of studies evaluating variation between the provenances in growth and
density of E urophylla have been carried out in tropical and subtropical
countries (Eldridge et al., 1993; Hodge et al., 2001; Ngulube, 1989; Darrow and Roeder, 1983; Wei and Borralho, 1997) Several provenances such as Mt Mandiri, Mt Lewotobi, Mt Egon have been assessed to be highly productive (Liang Kunnan, 2000; Liu Dehao et al., 2013; Turbull, 2003; Leksono Budi et al., 2015; Dlamini, 2017)
Narrow-sense heritability of diameter in E urophylla ranged from 0.09 to 0.60
(age from 2.5 to 17 years of age), narrow-sense heritability of height varied from 0.05 to 0.49 (from 2.5 to 7 years of age) Whereas, the heritability in the density of Eucalyptus wood generally fluctuated between 0.29 and 1.0 with an average value of 0.67 (Jun Lan, 2011), the narrow-sense heritability of pulp yield was 0.11 (Francois van Deventer, 2008)
Relationship between growth traits (diameter, height) is from strong to very strong (Leksono and Kurinobu, 2005) but genetic correlations between growth traits and wood properties (density, pilodyn) are often negative (Wei and Borralho, 1997; Lou Jianzhong, 2003; Ignacio-Sánnchez et al., 2005; Jun Lan,
Trang 72011) Therefore, depending on the goal of the breeding, breeders chose the
appropriate selection procedure for E urophylla
Correlation of the same trait at different ages (age-to-age correlation) of tropical Eucalyptus species for growth traits is usually very strong (Osorio et al., 2003; Wei and Borralho, 1998) Therefore, the selection of provenances/ families/
clones of E urophylla can be done from the age of 3
Wood cracks are caused by the pressure on growth, this pressure is released (commonly called growth stress) after cutting and cracks in the wood (Okuyama 1997) Therefore, it greatly affects the economic efficiency of the plantations of eucalyptus (Darshani and Amarasekara, 1996) The studies of Garcia and Lima suggest that the characteristic of the log splitting in some Eucalyptus varieties is under genetic control (Fégely, 2004) According to Nutto (2004), there is a correlation between growth stress and variety, so breeding and provenance selection can reduce the negative effects of growth stress
In addition to E urophylla improvement programs for E urophylla, Eucalyptus hybrid breeding programs between E urophylla and other Eucalyptus species
have been carried out in Brazil, Congo and China Research by Verryn (2000) showed that hybrid combinations were resistant to adverse environmental conditions, hybrid combinations had a superior crossbreeding advantage than pure species and were commercially grown in Brazil and Congo (Eldridge,
1993) Recent research in South Africa also showed that the hybrid between E grandis and E urophylla not only had higher wood properties but also had
better disease resistance than the parent species (Van den Berg et al., 2015)
1.2 In Vietnam
E urophylla was first introduced to Vietnam in the 1980s, they adapted to many types of bare hills, poor-nutrient terrain In Vietnam, Eucalyptus urophylla has been widely grown in the Central North, North Central and
Trang 8Central Highlands (Nguyen Duong Tai, 1994) Provenance trials for E urophylla have been conducted since the 1990s, the results show that the
provenances of Ulubahu, Lewotobi Flores, Egon Flores, Waikui Alor and Uhak are fast-growing at the period of 3-9 years (Nguyen Duong Tai, 1994; Le Dinh Kha, 2003; Ha Huy Thinh et al., 2006; Nguyen Duc Kien, 2009) Heritabilities
of growth traits of E urophylla in first-generation ranged from 0.10 to 0.31
Heritabilities for stem straightness and branch size are from 0.09 - 0.22 (Nguyen Duc Kien, 2009)
The E urophylla clonal trial later recognized some new varieties For example,
national varieties: PN2, PN14 (2000), PN3d (2005), technical progress seedling source: PN10, PN46, PN47 (2004), PN54, PN116 (2005), PN21, PN24, PN108 (2006) (Research Institute of Pulp and Paper raw materials tree species, 2014), U892, U1088, U821, U416, U262 (Ha Huy Thinh et al., 2015)
Studies on some properties of E urophylla have also been performed mainly
focusing on characteristics of density, wood shrinkage, pilodyn (Nguyen Duc Kien, 2009; Mai Trung Kien, 2014; Ha Huy Thinh et al., 2015) In which, the heritability of pilodyn (0.42 - 0.48), wood density (0.68 - 0.78) are high at the study sites, while the heritability of cellulose content is medium (0.25 - 0.31) Genetic correlation between growth traits and wood quality is often weak (between diameter and wood density ranges 0.15 - 0.28; between height and wood density ranges 0.11 - 0.19) (Ha Huy Thinh et al., 2015), to moderate (correlation of diameter with pilodyn is 0.26 - 0.46 and the correlation between height and pilodyn is 0.05 to 0.21) (Mai Trung Kien, 2014) The correlation between growth traits and stem quality ranged from medium to high level (among diameter, height and stem straightness, branch size 0.21 - 0.61; among diameter and height from tight to very tight (0.75 - 0.98) ) Correlation between density and pilodyn is quite strong (0.80 - 0.92) (Nguyen Duc Kien, 2009; Mai Trung Kien, 2014; Ha Huy Thinh et al., 2015)
Trang 9Age-to-age correlation: the correlation of diameter and height in the pair of 3 -
5 ages is the highest Therefore, it can be confirmed that at the age of 3, we can select fast-growing families and ensure high reliability (Mai Trung Kien, 2014)
In particular, research on log-end splitting in E urophylla has been initially
conducted (Nguyen Quang Trung, 2009) However, research on log-end splitting is just an applied study and more processing-oriented than the study of
breeding for log-end splitting character of E urophylla
In addition, previous studies have determined that E urophylla was capable of breeding with other Eucalyptus varieties (Eucalyptus camaldunensis, Eucalyptus tereticorrnis, Eucalyptus exserta and Eucalyptus grandis) to create
outstanding hybrids advantage (UP, UE, UC) (Nguyen Viet Cuong, 2002; Mai
Trung Kien, 2014) Crossbreeding studies and hybridization trials between E urophylla and some other Eucalyptus have been carried out since the 1990s The results show that all of the hybrids of E urophylla is rapid growth (Le Dinh
Kha, 2001; Nguyen Viet Cuong, 2002) The influence of father-mother tree is relatively clear on the growth performance of hybrids, especially in the more favourable growing conditions, the more hybrid heterosis is (Le Dinh Kha, 2006)
Through hybrid breeding, the fast-growing hybrid combinations were selected (Nguyen Viet Cuong, 2006), from the results of clonal trials, some Eucalyptus hybrid clones was recognized as national and technical advanced varieties: UP35, UP72, UP95, UP97, UP99, UP54, U892, U1088, U821, U416, U262, UP153, UP164, UP171, UP180, UP190, UP223, UP236, UP23, UP96, UP89
(Ha Huy Thinh et al., 2015) Nowadays, E urophylla or hybrids between E urophylla and other Eucalyptus varieties are widely used in production in our
country (Ha Huy Thinh, 2015)
Trang 101.3 Insight from literature review
Research on variation and genetic ability, genotype interaction of E urophylla
for the first generation has been studied methodically in Vietnam Continuous assessment of growth and wood properties on the degree of variability and genetic parameters in second-generation progeny trials is essential to develop breeding improvement strategies in the future On the other hand, the breeding process also creates high-quality varieties for mass production
The hybrid between E urophylla and another species has better growth and
resistance to unfavourable conditions and insects than their parents Studies on Eucalyptus hybrids breeding show that Eucalyptus hybrid has great growth potential and excellent adaptability to many types of site and climates Therefore, research, testing and evaluation of wood properties of new hybrids carry not only scientific meaning but also productive one when new varieties with high yield and quality are selected and can be put into production, increasing the diversity of the plantation as well as ensuring the bio-security of the clonal plantations
In addition to the growth characters, the wood mechanical properties, especially
the wood cracking parameters of E urophylla when planted in large timber
plantations need to be considered However, up to now, research on crack has been concentrated in the processing sector but no breeding study This is a field
of research that needs additional research in breeding programs for E urophylla
and their hybrids
Trang 11Chapter 2 CONTENT, MATERIAL AND RESEARCH METHODOLOGY 2.1 Research objectives
1) Research about genetic variation related to growth and trunk quality on E urophylla in second-generation progeny trials
- Study on the level of genetic variation in growth and stem quality of E urophylla families in the second generation progeny trials in Ba Vi - Hanoi and
Nam Dan - Nghe An
- Study on the genetic variation in some wood properties of E urophylla
families in the second generation progeny trial in Nam Dan - Nghe An
- Evaluation of heritability and genetic correlation between research traits
- Selection of elite individuals and families in second-generation progeny trials
2) Research on growth and wood properties of hybrids between E urophylla
and other Eucalypts (UP - PU, UG, UC, CP – PC) and selection of hybrid combinations and individuals have fast growth in the trials
2.2 Research materials
- E urophylla varieties group includes 154 families from 4 provenances in
second-generation progeny tests (ages of 10 and 15) in Hanoi and Nghe An (age of 8 and 13)
- Eucalyptus hybrid groups includes 95 hybrid combinations from 52 different
mother trees (33 E urophylla mother trees, 3 E camaldunensis mother trees, 16
E pellita mother trees) which were used to set up hybridization trials in Ba Vi
(ages of 3, 6 and 8), Quang Tri (ages of 5 and 8) and Binh Duong (age of 4)
2.3 Research methodology
2.3.1 Field data collection
a) Growth data collecting method according to Vu Tien Hinh and Pham Ngoc Giao (1997)
Trang 12b) Investigating trunk quality method
- Stem straightness (Dtt), branch size (Dnc): is group according to 5 levels (scale from 1 to 5 points) according to Vietnam standard 8761: 2017
- Heath indicator: determined by visual assessment and according to 5 levels (scale from 1 to 5) (Le Dinh Kha & Duong Mong Hung, 2003)
- Synthetic quality index Icl (Le Dinh Kha & Duong Mong Hung, 2003)
2.3.2 Methods of determining the physical and mechanical properties of wood
a) Determining wood density by applying water displacement method (Olesen, 1971)
b) Determining shrinkage according to Vietnam standard TCVN 8044:2009 c) Determining log-end split parameters according to Nascimento et al., 2019 and Yang et al., 2005
d) Indirect evaluating wood elastic module (MoEd) using Fakopp equipment according to the method of Raley et al (2007)
2.3.3 Data analysis
Data analysis were used DATAPLUS 3.0 and Genstat 12.0 (VSN International) and ASREML 4.0 (VSN International)