Managing a model population to market the potential of breeding  Tree breeding characteristics þ Model population Goals Techniques þ Breeding strategies Standard Model Combined þ Advantages/disadvantages Bengt Andersson, SkogForsk, Box 3, SE Sävar, Sweden

Breeding of forest trees  Long generation intervals þ Low genetic gain per time þ Postponed return from breeding investments

Breeding populations for - increased yield - climatic change prep. - gene conservation Photoperiod (latitude) Temperature climate (growing season days)

Model population Primary goals ù Shorten generation time to 1/3 ù Unchanged gain ù Unchanged diversity Operational size ù 19 selected parent trees (50 normally) ù 20 full-sib families (50 normally) ù 760 candidate trees (500 normally)

Model population - components þ Exclude time lag for sexual maturity Vegetative propagation Clonal testing þ Early tests for evaluation/selection NIR (Near InfraRed reflection) for hardiness MI (Mitotic Index) for growth Field performance for 2nd stage selection þ Early flowering for generation turnover Top-grafting with young scions Accelerated growth of selected individuals

Model population - components þ Exclude time lag for sexual maturity Vegetative propagation Clonal testing þ Early tests for evaluation/selection NIR (Near Infrared Reflection) for hardiness MI (Mitotic Index) for growth Field performance for 2nd stage selection þ Early flowering for generation turnover Top-grafting with young scions Accelerated growth of selected individuals

Fig. Breeding values (BLUPs) of 13 Scots pine clones, based on progeny performance in field trials. (Andersson) superior average

Julian day MI Fig. Mitotic index (MI) from pooled superior (  ) and average (  )clones between April 25 and Oct. 24. (Sundblad et al.)

Fig. Predicted damage (Near Infra Red reflection - NIR) and observed damage after freezing (Electrolytic Conductivity - EC), of Scots pine seedlings from latitude (Sundblad et al.) Predicted damage (NIR) Observed damage (EC)

Top-grafting for early flowering

Year Year 50 P, dpm 500 F1 candidates pc F2 progeny trials evaluation F2 selection 50 F1, dpm 50 P, dpm selection 50 F1, dpm early test evaluation 8 veg. prop. 500 x 10 top-grafting 4 Standard strategy Model strategy

0 50 P, dpm Year Combined strategy - an example 2 50 x 40 F1 candidates veg. prop x 10 (top-grafting) 4 8 early test evaluation, (top-grafting), transplanting to field primary selection 50 x 4 F1, dpm 200 x 10 F2 candidates 10 veg. prop x early test evaluation, field test evaluation final, combined index selection 100 x 2 F2

Model population - concluding remarks þ Strong points Substantial time reduction possible Techniques seem promising Each activity independent of others þ Weak points Techniques still need development Selections based on early tests Culling (vegetative prop., early flowering)