Genetic Improvement of
Forest Trees
Khongsak Pinyopusarerk
CSIRO/Ensis-Genetics
Canberra, Australia
Why Do We Need Tree
Improvement?
To develop new plantations superior
to their predecessors in one or
several key economic traits.
Variation within
a Species
Offer potential for
improvement
through selection
and breeding
between provenances
between families
Basic Elements of Tree
Improvement
• Well defined strategy and plan
• Clear objectives
• Hierarchy of populations
• Selection and mating
• Personnel and funding
Well Defined Strategy and Plan
• Improvement strategy – the framework of
ideas. Essential elements are:
(a) Type of selection and mating, starting with a broad
genetic base
(b) An efficient system for mass propagation of

• fodder value
• other traits?
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Activity Cycle –
Hierarchy of Four Populations
Base
population
Breeding
population
Propagation
population
Production
population
BASE
progeny
tests
seed
orchards/
clone banks
plantations
selection
mass
propagation
select trees
mating
Propagation

Controlled Pollination
Improvement Program of
Acacia auriculiformis
Good progress in Thailand and Vietnam
Hybrids
• Natural or artificial
• Heterosis in F
1
generation
Hybrids
Uniformity of F
1
generation
Segregation of F
2
and subsequent
generations
Seed Production Area
Î Low-cost technology
• Establish stands with a mix of 50-
100 unrelated seed parents from
many sources
• Start at close spacing to allow
heavy and early selective
thinning
• Produce seed of somewhat
improved quality
• Outstanding individuals may be
used for clonal forestry after field
testing