Tree Breeding and Selection for the Future Elspeth Macdonald & Steve Lee, Forest Research
Thanks to Barry Gardiner, Shaun Mochan, Stuart Kennedy, Andrew Cameron and John Moore
Timber Quality Steering Group 26th October 2011 Outline
• Gains from Sitka spruce breeding programme • Wood and timber properties from improved Sitka spruce • Improving mechanical properties through breeding • Screening in young trees Gains from Sitka spruce breeding
• Predicted volume gains of around 25% • Straightness and branching – improvements of up to 15% • Wood density – little or no reduction • Up to date information about predicted gains from seed orchards and “family-mixtures” is available at: www.forestry.gov.uk/fr/treeimprovement Wood and timber properties Recent studies have looked at the wood properties and timber performance of improved Sitka spruce:
Kershope study – 38 year old half-sib progeny trial ¾ Volume and assortments ¾ Structural timber performance ¾ Wood properties in clear wood samples Volume Recovery
250%
Potential Green Log Volume Potential Batten Volume Potential Batten Volume/ha 200%
150%
100%
50%
0% 445 Farigaig 430 Ratagan 140 Glenbranter QCI C16/C24 pass rate
120% C16 Pass Rate C24 Pass Rate
100%
80%
60%
40%
20%
0% 445 Farigaig 430 Ratagan 140 Glenbranter QCI Clear wood properties
12 QCI Family 2 10 Family 3 )
2 Family 4 − mm
N 8 (k E MO 6
4 100
90 ) 2 − 80 mm
(N 70 R
MO 60
50
40 0 5 10 15 20 25
Ring Number Sitka Spruce Wood Stiffness 300 Mean MOE C16 requirement
250
200 y nc
ue 150 q e Fr
100
Large amount of variation 50
0 468101214
Modulus of Elasticity (kN mm−2) Breeding to improve stiffness
• Selecting for density alone may not safeguard mechanical properties • Screening for stiffness as well as density is likely to offer greater gains in mechanical properties • Acoustic tools offer a rapid, non- destructive method for assessing stiffness • Drying distortion is influenced by some of the wood quality traits that determine stiffness (grain angle, microfibril angle) – improving stiffness should improve dimensional stability Potential for improvement
• Recent PhD at Aberdeen University (Stuart Kennedy) investigated potential for improving Sitka spruce mechanical properties through selection • Tested 20 year-old half-sib trial • Results: ¾ Wood quality traits all moderately heritable, i.e. scope for improvement through breeding ¾ Negative correlation between growth rate and stiffness, strength, wood density and microfibril angle ¾ BUT some families have superior growth, stem form and wood quality traits → breeding from these could offer gains in timber production and performance Growth rate and stiffness
QCI Selecting for stiffness
• New project with Aberdeen University • Study sites: 26 year-old full sibling progeny trials at Strathyre (mid Scotland), Spadeadam (N. England) and Radnor (Wales) • Includes families available in commercial breeding population • Assess wood stiffness (acoustic tool), density
(Pilodyn) and diameter Photo courtesy of Fakopp Enterprise, Hungary Spadeadam progeny trial Selecting for stiffness
• Determine breeding values for wood stiffness, compared to QCI control • Identify families with improved growth and wood stiffness • Destructive sampling and timber testing to analyse mechanical and physical properties • Selection for further breeding will be informed by results
Photos courtesy of Stuart Kennedy Early screening for wood stiffness • Acoustic tools • Sapling tool will be designed for small tested and validated trees offer the with Sitka spruce opportunity for earlier screening for wood stiffness in the breeding programme
Photos courtesy of Fakopp Enterprise, Hungary Conclusions
• The Sitka spruce breeding programme has delivered gains in timber volume production, stem form and branching • Improvements in mechanical properties (and perhaps drying distortion) could be achieved by selecting for wood stiffness as well as wood density • Portable acoustic tools offer a means of screening for wood stiffness in young trees… • …to inform breeding programme and achieve improvements quickly through controlled pollination and vegetative propagation