Transcript Slide 1
FOREST TREE
IMPROVEMENT
DR. AB. RASIP BIN AB. GHANI
DIRECTOR
FOREST PLANTATION PROGRAMME
BIOTECHNOLOGY DIVISION
FOREST RESEARCH INSTITUTE MALAYSIA (FRIM)
KEPONG, 52109 SELANGOR DARUL EHSAN, MALAYSIA
TEL: +603-62797097
FAX: +603-62731427
EMAIL: [email protected]
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GENERAL CONCEPTS
OF TREE
IMPROVEMENT
Forest Genetic
Forest tree breeding
Tree Improvement
Step involving in TI
Why we need tree improvement?
Important consideration
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Tree Improvement (TI)
Forest Genetic – genetic studies of forest trees
Forest tree breeding – studies on some specific
problem to produce a specially desired product
Tree Improvement – combination of all silviculture and
tree breeding skill to grow the most valuable forest
product as quickly as possible and as inexpensive as
possible
Step involving in TI
• Species determination – geographic source
• Variability studies - amount, kind and causes of
variability
• Packaging of desired quality into improved
individual
• Mass production of improved individuals
• Developing and maintaining a genetic base
population broad enough for needs in advanced
generation
Why do we need TI?
• Intensive tree farming
Production of the desired quality timber in maximum
amounts in the shortest period of time at reasonable
cost
TI:• Improved yields and quality on the more productive
forested area
•Can grow tree on land that are sub-marginal and no
economic for timber production
•Develop strains that are more suitable for specialized
products or uses
Important consideration:Time >
Cost >
Quality
VARIATION AND ITS
USE
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Genetic variability
Environmental variation
Variation caused by man
Racial variation
Mating system
Factors shaping variation
Selection
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Basis for selection
Especially on the economic traits
Must determine the amount, cause and the nature of
variation
The variations in tree species are generally high
Strategy for survival
Long life
Expose to various environmental condition
Giving more opportunity for selection
Basis of variation
At cell level >>>>>> Chromosomes and gene
Causes and kinds of variability
Basically the differences among tree resulted from
i. The differing environments in which the trees are
growing
ii. The genetic differences among trees
iii.The interaction between the tree gene types and
environment in which they grow
P = G + E + GxE
G = genetic
E= environment
GxE = interaction between G&E
Environmental variation
Soil >> Light >> H2O >> Space
Effect on tree – competition among trees.
Factors can be controlled in Silvicultural practices
Genetic Variability
Genetic variation = additive gene action +
non-additive gene action
2P = 2G + 2E
2G = 2GA + 2GNA
2P = 2GA + 2GNA + 2E
Additive gene action = cumulative effects of all gene
loci influencing trait
Non-additive divided by two
i. Dominance – interaction of specific affects at a
gene locus
ii. Epitasis – interactions among gene loci
Most characteristics of economic importance controlled
by additive gene action
Additive variance can be used in simple
selection. e.g. wood density, bole straightness
non- additive – e.g. growth rate
Pest resistance – both additive & non- additive
SOURCE OF PLANTING
MATERIAL
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Seed source
Strategies of acquiring planting material
Short-term strategy
Long-term strategy
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Source of Seed
The importance of source of seed
• Success of plantation depends on seed source
• Largest, fastest and cheapest gain can be realized
through proper species and seed sources
Terminology:
Adapted
– how well trees are physiologically suited
for high survival, good growth, resistance to P & D and
adverse condition
Exotic - tree grown and of its natural range
Provenance, geographic source or geographic race
• denote the original geographic areas from which
seed or other propagules were obtained
Seed source – or origin
Racial variation
• natural population
• between individual within population variation – racial
variation
Clines and ecotypes
Cline – a gradient in a measurable characteristic
which follows environmental gradients.
Variation may/may not base on genetics.
Ecotype – a group of plants of similar genotype that
occupy a specific ecological niche
Land race
• A population of individuals that has become adapted to
a specific environment in which it has been planted
• Can be the easiest and best way of making quick and
large genetic gains
Where races are developed best?
i. Species with very wide range over environments
ii. Species growing a wide altitudinal range
iii.Species that grown in regions of greatly diverse
soils
Where to select?
• Safest method is to select local source
• Outside source that have been proven better
• From center of origin
Steps to select seed source
1. Make decision about the objective of the plantings
and the products desired
2. Obtain all information possible
3. Survey the area for any plantation of desired
species- develop S.P.A
4. Determine the variation within the seed source or
provenance
5. Operationally used seed from initial land race or
best potential provenance while better source being
developed (through breeding activity)
Selection of Plus tree
• Candidate Plus tree
A tree that has been selected for grading because of its
desirable phenotypic qualities but has not yet been graded
or tested.
• Selected, superior or plus tree
A tree has been recommended for production or breeding
orchard use following grading. It has superior phenotype for
growth, form, wood quality or other desired characteristics
and appears to be adaptable.
• Elite tree
Plus tree that has been proven to be genetically superior
by mean of progeny testing.
• Comparison trees
Trees that are located in the same stand and against which
the candidate plus tree is graded.
• Advance
Generation selection – A tree selected from genetic test of
crosses among parents from previous generations.
Selection
Individual tree selection / mass selection
• Even – aged stands
Concentrated on stands and plantation that
average or better performance
Same site quality to the plantation
Known seed source
Medium – aged stands
Pure species composition
Avoid logged over stand
Large enough for selection and comparison trees
Emphasis on high seed production
Thorough and systematic search
Used comparison tree method
Uneven aged stand
Regression selection system
A
Volume growth
B
Regression line
Age of trees
C
Selection of plus tree
Teak plus tree
Strategies in satisfying the need of planting
material
Short term strategies
1. Proven
provenances (provenance trial/ GxE
interaction)
Acacia mangium : Oriomo river (PNG)
Claudi River (Northern Territories, Aust)
Pinus caribaea : Hondurus
2. Land Races
A. mangium
Rubber
Oil palm
3. Plus trees
• Seed, vegetative materials
4. Seed Production Areas/Seed Stands
poor phenotypes are rogued from the stand and
good trees are left to intermate.
Long Term Strategies
1) Clone establishment
From Plus/Elite trees
Vegetative propagation
Macro - grafting
- layering
- cutting
Clone banks/ Research orchards
Clone test
Clonal Forestry
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Uniformity
Adaptation
Cost
Wood production
Deployment of GMO’s
Deployment of hybrids and expensive rare seed
The opportunity to gain a better understanding of
individual genotype overtimes and oversight
Teak tissue cultures multiplied in test tubes
Biotechnology
Tissue culture
Teak tissue cultured plants ready for
field planting
Teak plantation
established
2) Seed orchard
a) Seedling seed orchard
Plus trees/elite trees
Seed
Set up seed orchard
Progeny trial
Improved seed orchards
b) Clonal seed orchard
Plus trees/elite trees
Vegetative material
Set up seed orchard
Progeny trial
Improved seed orchards
Hybrids
• To combine complimentary traits of two parents
• To exploit hybrid vigour (heterosis)
• Increase the adaptability for afforestation into
marginal areas for that species
Acacia hybrid
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QUANTITATIVE
ASPECTS OF TREE
IMPROVEMENT
Genetic values
Heritability
Selection differential and selection intensity
Genetic gain
Method to obtain gain
Mating design
Experimental design
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Statistical aspect of FTI
Genetic value
- To get the best set of parent trees for breeding.
P = G + E + GxE
Progeny trial
- Evaluate the parents through the performance of
the progenies.
- eliminate the E effect by giving the same
environment
Genetic value is express in term of Combining ability
General Combining Ability (GCA) – the average
performance of the progeny of individual when it is
mated to a number of other individual in the
population.
Specific Combining Ability –the average performance
of the progeny of a cross between two specific parents
that are different from what would be expected on the
basis of their general combining ablity alone.
e.g:
Female
parents
1
2
3
4
5
9
17
12
14
13
6
10
16
12
10
12
7
11
20
10
15
14
8
14
15
6
17
13
Progeny
means
11
17
10
14
Test Means 13
Male parents
Progeny means
For parent 2 (male)
GCA = mean of parent 2 – test mean
= 17 – 13 = +4
parent 2 has general ability (GCA2) for volume of
+4
Breeding value of an individual is defined as twice its
general combining ability.
Breeding value = 2 (GCA)
BV parent 2
= 2 (GCA2)
= 2x4=8
SCA – it always refer to specific cross and never to a
particular parent by itself.
3 steps in calculating the SCA :
e.g Cross between parents 3 and 6 ( a cross value of
12)
Calculate the GCA for both parents
GCA3= -3; GCA6 = -1
Calculate the anticipated value of the cross
(Summation of test mean and the GCA for both
parents)
Anticipated value = test mean + GCA3 + GCA6
= 13 + (-3) + (-1) = 9
Subtract the value calculated in (2) from observed
value of the cross.
SCA3x6 = observed value – anticipated value
= 12 – 9 = +3
This means that cross 3 x 6 is performing 3 volume
unit better than would be expected based on the
GCA’s of parents 3 and 6.
Genotype X Environment interaction
The
relative performance of clones, families,
provenance or species differ when they are planted in
different environment.
Situation 1
Seed lot
Location 1
Location 2
Location 3
Location 4
1
23
25
26
22
2
24
27
27
23
3
20
24
25
21
Seed lot
Location 1
Location 2
Location 3
Location 4
1
23
27
26
22
2
24
25
25
23
3
20
24
27
21
Situation 2
Analysis of variance
Analysis of variance
Heritability
1) Broad-sense (H2)
The ratio of all genetic variance to the phenotypic
variance
2G
2A + 2NA
H2 =
=
2
P
2A + 2NA + 2E
2) Narrow-sense (h2)
The ratio of additive genetic variance to phenotypic
variance
h2 =
2A
2P
=
2A
2A + 2NA + 2E
Selection differential
The difference between the mean of selected
individual and the population mean
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S= Xs- X
Genetic gain
G= h2 x S
Or for juvenile
G= i h2P
i
= intensity of selection
h2 = heritability
P = phenotypic standard deviation
TREE IMPROVEMENT
STRATEGY
• Objective
• Factors for consideration
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Factors for Consideration
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Objectives of plantation
Manpower
Financial
Land
Time
A conventional breeding strategy
Nucleus breeding strategy (Cotteill; 1989)
Multiple breeding population-Breeding seed orchard strategy (Barnes; 1984)
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