THE IMPACTS OF TREE IMPROVEMENT
PROGRAMMES ON FOREST HEALTH:
THE PAST MODELS, AND FUTURE
APPROACHES NEEDED IN CHANGING
CLIMATES
Alvin Yanchuk,
Forest Genetics Section, Research Branch, B.C. Forest Service,
Victoria, B.C. Canada
Gillian Allard,
Forest Health Officer, Forestry Department, FAO, Rome, Italy
1
Predicted range and frequency for
Douglas-fir in British Columbia
Present
2025
2085
2055
<5%
5 - 10 %
> 10 %
Source: Hamann A. & T. Wong. http://genetics.forestry.ubc.ca/hamann/
2
Climate and pest range shifts under future
warming predictions; e.g., Nun moth
3
Climate and pest range shifts under future
warming predictions; e.g., Gypsy moth
4
mountain pine beetle
mortality in lodgepole pine
Dothistroma needle cast
5
Response curves for ‘Nelson Low’ and ‘Prince
George Low’ populations of lodgepole pine in BC
(from, Wang et al. 2006, Global Change Biology)
Figure 6. Growth response curves of populations for 20-year height and volume per
hectare versus mean annual temperature (MAT).
6
Optimization of best populations in 8 seed planning
zones of lodgepole pine in BC (from, Wang et al. 2006,
Global Change Biology)
7
A long history pest and disease
resistance research in forestry….
1966
1992
In 2005, FAO initiated a survey of the
literature to document status / impact of
tree improvement programs addressing
disease and pest resistance
2003
1996
8
9
Categories / Status
1.
2.
3.
4.
Breeding programmes with deployed resistant material;
Programmes breeding for resistance, no deployed material;
Resistance detected in genetic/provenance trials;
Evidence in genetic variation in resistance in small research
seedling or clonal trials.
The information is also categorized under three broad approaches:
1. traditional plant breeding methods;
2. molecular biology approaches;
3. genetic engineering.
Tree Improvement and Breeding Programs for
Pest and Disease Resistance…..summary
• ~ 260 resistance ‘research programmes / initiatives’
identified
• ~ 20 programmes are using or have identified
resistance materials
• only 4-5 major commercial forestry programmes have
documented ‘impacts’
• substantial investments have had to be made in these
4-5 large commercial programmes, over a period of
several decades
• transgenics – most are with poplars in China
• ongoing survey: additional projects making impacts,
particularly in smaller programmes / countries?
Disease resistance breeding
• western white and sugar pines
– blister rust resistance
– USDA For Serv (Moscow, ID; Doreena, OR)
– BC MoFR and Canadian Forest Service
• loblolly and slash pines
– fusiform rust resistance
– NCSU / U. Florida / WGTIP
• radiata pine
– Dothistroma (For Res Inst., Rotorua)
• poplars (e.g., Greenwood / Mead-Westvaco /
many European countries)
–Melampspora
–Septoria
–Venturia
• chestnut blight (TACF)
12
Pest resistance breeding
• white pine weevil (B.C.)
• aphids on spruce (DK,UK)
• poplar beetles and borers
(China, US)
•>> eucalyptus – leaf beetles
•>> mammals- eucs, redcedar
•>> birch borer / ash borer
•>> adelgids in spruce
•>> bark beetles
•>> etc
13
Overview of Current BC Programs
• Changing directions of trait
objectives
– Growth and form selected in first
generations
• Pest resistance ‘models’
– Spruce (weevil)
– Pine (bark beetle)
– Redcedar (deer)
• Disease resistance ‘models’
–
–
–
–
White pine (blister rust)
Redcedar (needle disease)
Douglas-fir (root rot)
Pine (gall rusts)
Sitka spruce clone #898 – immune to all attacks todate!
?
Breeding and deploying deer resistance
western redcedar
• Browse correlated
with needle
monoterpenes
• Genetic variation in
monoterpenes
30000
total needle monoterpenes (ppm)
• Observed variation
in browse among
trees
25000
20000
15000
10000
5000
0
0
10
20
30
50
40
% failed
16
60
•Western redcedar browse resistance
Family mean BLUP effects for 5 year height and needle
atredcedar
redcedaropen-pollinated
concentrations
alpha-thujone content in•Thujone
a western
family trial
height (cm)
rg=0.27
-4000
•thujone
-3000
•Control
apples consumed (g)
control
100
8
80
6
60
4
40
2
20
-2000
-1000
0
Antoine
0
-2 0
-4
Arthur
-6
-8
thujone
1000
JeanLouis
Barb
2000
Louise Mélusine
3000
Tania
Deer
-10
•Monoterpenes in redcedar
appear
‘repellent’ to deer!
alpha-thujone
(ppm)
17
18
?
delta-3-carene
19
Will this approach serve us well
into the future?
•
Pests and diseases we will be facing?
– Shifting species and population ranges into new
environments
– Increased activity/damage in current distributions
– Continuing exotic pest and disease introductions
•
Can’t afford to develop specific
resistances to pest ‘x’ or disease ‘y’?
– 15 - 40 years per programme to develop and
deploy resistant material?
•
5 additional issues we must consider
are…
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1. Resources for pest and diseases
resistance breeding….?
• We will likely have fewer resources to
incorporate specific host-pest resistance
mechanisms
– Tree breeders, entomologists, pathologists interested in
screening / phenotyping and working together?
• Dwindling investments and take up of tree
improvement programs
– TIMO’s, REIT’s, corporate ‘disintegration’
– Use of ‘cheapest seed’
– Global reductions in basic plant breeding and
quantitative genetic training
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2. Innovation in applying
resistances
• Finding specific mechanisms has been
extremely difficult
– after ~150 papers on mountain birch herbivory
(Haukioja. et al.)… still no clear understanding,
e.g.,
• Large spectrum of compounds that change over
the growing season
• Resistance varies by herbivore spp.
• Changes in nutrients, water content and leaf
toughness as important as any chemicals
– general mechanisms against ‘classes’ of
pests?
– may be more difficult with diseases?
• Large investments in host-pest /
disease research is still being made,
however;
– better $ alignment with applied programmes
that deliver resistant germplasm, if possible
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3. Studies on non-pedigreed trees
• Studies on wild trees, while
important for modelling
natural disturbances, they
may not;
– be able to extrapolate work to
facilitated migration of species /
populations under climate
change
• Working with pedigreed
material from breeding
programs, if available, can
still provide basic information
23
Distribution
of long-term
genetic field
experiments
in B.C
•Map of our 1000 tests
• Currently
>1000 field
installations!
• range in age
from 1 to ~50
24
EP 513 Coastal Douglas-fir Provenance Test
• Represents millions of dollars of investment
•
database management
•
documentation
•
security
• Annual maintenance expenditures in the order of $350k / yr
25
4. Further Investments in Molecular
Genetics
• Out pacing investments in
applied and traditional
breeding technology!?;
– 30% of the ‘initiatives’ were
molecular based approaches
(over the last 10 years)
– of great biological interest, but
need to be better aligned with
applied programmes
– e.g., phenotyping on seed
orchard clones?
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5. Transgenic trees
• Address immediate local
insect or disease problems
(e.g., use of Bt)
• Still have to operate within
well developed breeding
programmes
– Adequate field testing
– Populations must be managed at the
landscape level
• particularly with a climate change ‘lens’
• gene flow to wild relatives
• consider evolution of virulence or
resistance
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Building resistance ‘portfolios’ to
classes of biotic challenges?
Spruce
Genotype
1
2…
…100
Yes
No
Yes
No
Yes
No
Yes
Yes
No
Good
Average
Average
Yes
No
No
Yes
Yes
No
Yes
No
Yes
No
Yes
Yes
Pine
Genotype
1
2…
…80
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Conclusions:
after 50 years of tree breeding…
•…relatively minor global impacts of resistance breeding,
however;
– some, locally very important successes
– few species have the tree improvement ‘machinery’ in place
– substantial research not directed on problems where
silvicultural management options are limited (e.g., Pw, chestnut)?
• New approaches necessary?
– better focus of resources?
– general ‘mechanisms’ of resistance (i.e., cross resistance?)
• Finding resistance genotypes is not our main challenge;
– test our current resistances/genotypes across ‘new’ classes of pests
and diseases resistance (i.e., cross resistance?)
– can we build the internal capacity to do so?
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Thank you!
Photo: A. Woods
AcknowledgementsJohn Russell, John King,
Barry Jaquish, Mike
Carlson, Nick Ukrainetz
Every really new idea looks crazy at first.
Alfred North Whitehead (1861-1947)
The important thing is never to stop questioning.
Albert Einstein
If you want to make enemies, try to change something.
Woodrow Wilson (1856-1924)
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