Forest Tree Breeding and Challenges

Transcription

1 Forest Tree Breeding and Challenges Harry Wu SLU Plant Breeding Platform November , Uppsala, Sweden

2 World Forest and Plantation Total area 4 billion ha Net loss per year=7.3 m ha Sweden=23 m ha 0.58%

3 World Forest and Plantation Productive forest plantation = 120 m ha

4 World Forest and Plantation Productive Plantation ~ 40 m ha ~ 13 m ha ~ 14 m ha 12%

5 Presentation Outline 1. Tree breeding process 2. Tree breeding population and breeding strategies 3. Example of two advanced tree breeding programs Radiata and loblolly pine 4. Genetic gain from tree breeding 5. Major breeding and deployment issues 6. Perspectives and opportunities of tree breeding

6 Tree Breeding Process Breeding population Improved varieties Selection Cross pollinisation Progeny tests

7 Tree Breeding - Large Base Population Radiata pine 1213 plus tree selection (STBA, Australia) Loblolly pine 3800 selections (NCSU-ICTIP, USA) Scots pine 6000 plus tree selection (Skogforsk, Sweden) Blue gum 1516 plus selection (STBA, Australia)

8 Tree Breeding - Large Breeding Population Radiata pine 300 (STBA, Australia) Loblolly pine 160 elite (NCSU-ICTIP, USA) Scots pine 1000 (Skogforsk, Sweden) Blue gum 300 (STBA, Australia)

9 Varied Breeding Strategy Cotterill 1988 Namkoong 1976, Burdon and Namkoong 1983 Van Buijtenen and Lowe 1976 Burdon 1976 Burdon and Namkoong 1983

10 Varied Breeding Strategy Generation Population 1 Population 1 Population 1 P P D. Single population with rolling-front (operation) breeding strategy Feature No discreet generation Crosses and new trials are made each year Advantage Greater gain per year due to high selection intensity Disadvantage Need sophisticated software for BV prediction and for inbreeding control P Borralho and Dutkowsks 1998

11 Varied Breeding Strategy generation E. Inbreed-hybrid breeding strategy 1 self S0 self S0 Feature: 1. Selfing for several generations to purge deleterious genes 2. Best lines for cross to create heterosis 2 self S1 self S1 Advantage: 1. Fast purge of inbreeding depression 2. Create large heterosis 3 S2 S2 Disadvantage: 1. Long-term inbreeding 2. Fixation of deleterious alleles Hybrid Wu et al 2004

12 Hybrid Breeding Strategies Pure species A Pure species B Selection Selection F1 Selection Selection F1

13 Ten year old hybrid between E. grandis and E. urophylla

14 Example of radiata pine breeding in Australia Early commercial plantations First generation Plus trees ( ) Open-pollinated clonal seed orchard Half-sib progeny testing Full-sib progeny testing Second generation breeding population (1992) Control-pollinated clonal seed orchard Full-sib progeny testing from 1996 Fourth g. breeding population 2011/12 Third g. breeding population from 2002 Full-sib progeny testing from 2003/04 Multiple deployment populations Wu et al 2007

15 Open-pollinated seed orchard

16 Control-pollinated seed orchard - hedged

17 Example of loblolly pine tree breeding program in USA Fourth generation scions selected and topgrafted in 2012

18 Achieved Genetic Gain Radiata pine (New Zealand/Australia/Chile) Fourth generations (genetic gain 30+11=41%) G0 Loblolly pine (USA) Fourth generations (genetic gain 30-40%) Hybrid E. grandis and urophylla (Brazil) Hybrids improvement (one generation % gain) G1 G2

19 Major Breeding and Deployment Issues A. Controlling inbreeding (co-ancestry) B. Managing negative genetic correlation C. Capturing genetic gain in deployment A. Clonal forestry B. G by E interaction D. Shortening breeding cycle

20 A. Controlling Inbreeding Example of radiata pine: Best 300 selections in the 4th generation = effective population size (N e ) ~ 20

21 B. Managing Negative Genetic Correlation in Multiple Traits 150 Diameter and Wood density Norway spruce 5618 trees 100 Genetic correlation: , Chen et al. 2014

22 C. Capturing Genetic Gain in Deployment Family deployment VS clonal deployment Family deployment Clonal deployment

23 D. Shortening Breeding Cycle Tree breeding process = 12 years = 22 years Selection Grafting and mating 5-10 Testing 7-12

24 Perspective of Tree Breeding in -omics Age 1. Using genomic information for simulation Optimal breeding strategies for controlling inbreeding (inbreeding or outcross breeding strategy) Dealing with negative genetic correlation (single and multiple breeding population) Hallingbäck et al. 2014

25 Perspective of Tree Breeding in -omics Age Seed Containing Embryo Establishme nt of New Clones 2. Capturing genetic gain using Somatic Embryogenesis 6 Embryo Culture 1 Mass Production of Somatic Embryos 2 Automated Sowing of Somatic Embryos Long Term 3 Frozen Storage Nursery Production Somatic Seedling 4

26 Perspective of Tree Breeding in -omics Age 3. Genome-wide association and genomic selection Use as a first-stage nursery (early) selection to increase selection intensity Use very early selection to shorten generation interval Testing 7-12 yrs 1-2 yrs

27 Perspective of Tree Breeding in -omics Age 4. Early flowering Use genomics, proteomics or metabolomics to accelerate the flowering for spruce and eucalypts Grafting and mating 5-10 yrs 2-4 yrs

28 Thank you Contribution of tree breeding to productivity

29 Blank

30 Developing Optimal Plant Breeding Strategy Using Genomics Harry X. Wu, S Henrik Hallingbäck, NS Complete additivity Partial dominance

31 Developing Optimal Plant Breeding Strategy Using Genomics Within 2 years Meta-data analyses to understand the genetic and genomic structure of quantitative traits Using genomic framework to simulate different breeding strategies of selfing and cross-breeding and population improvement Long-term GWAS to understand genetic control of agronomic traits at genome-wide level Dynamic simulation using whole genome genetic structure Using model species to conduct experiments to verify the optimal breeding strategy