Our group conducts research on forest genetics and tree breeding through understanding and dissecting genetic base of genetic variation for quantitative traits, including tree growth and form traits, wood quality traits, phenology traits, and biotic and abiotic resistance traits. The starting point is to investigate the genetic base of the phenotypic variation we observed between individual trees in forest stands. The first question we ask is how much of this variation between individual trees is due to genetic differences, and how much due to environmental factors. Then we need to find out the number of genes that are responsible for the genetic variation, and how these genes interact to influence the performance of trees in different environments. This basic knowledge can then be used in the design of breeding programmes for increased growth rate and quality of wood products in forest plantations.

Wu Harry 1150To design efficient breeding programmes and to increase genetic gain, we also need to identify the best native tree populations for selection and breeding for a specific forest region. This involves research on genotype by environment interaction and on response curves of existing populations and genotypes, so that we can delineate optimal breeding trees (population) that match the environment (breeding zone). After assembling a breeding population for further improvement, we need to design the best breeding strategy. We not only have to select the individuals that we want to use as a parent, to produce the best progeny, we also need to identify the ideal combinations of parents (mating design). Furthermore, we need to deal with inbreeding depression.

Another important question we need to address is how to deal with improvement of multiple traits that are adversely related, such as wood quantity vs. wood quality. First we need to find out the genetic causes of such correlation, using quantitative and molecular tools. Then we develop a gene model (locus and parametric model) and use simulations to identify the best selection and mating methods for dealing with such adversely correlated multiple traits. We also study the suitability of different mating and selection methods when it comes to avoiding or removing inbreeding depression in advanced breeding programmes.
Sampling for phenology and DNA in Scots pine Inspecting Eucalypt Plus Tree in China
Sampling for phenology observation and DNA in Scots pine  Plus tree in Eucalypts.

With the advance of gene sequencing technology, we start to study associations between individual genes or gene complexes with phenotype variation in trees. We study candidate genes or genome-wide approach to increase knowledge about the association between variations in DNA and observable phenotype variation. In addition, we are developing a quantitative genetics tool that integrates DNA sequence-based variation with phenotypic data, in order to improve the efficiency of genetic improvement in trees. This involves the development of advanced methods for breeding value prediction, such as genomic Best Linear Unbiased Prediction (G-BLUP) and Genome-wide Breeding Value (GBV).

Publication list

  1. Genetic analysis of wood quality traits in Norway spruce open-pollinated progenies and their parent plus-trees at clonal archives, and the evaluation of phenotypic selection of plus-trees
    Canadian Journal of Forest Research 2019, e-First Article
  2. Accuracy of genomic selection for growth and wood quality traits in two control-pollinated progeny trials using exome capture as the genotyping platform in Norway spruce
    BMC Genomics. 2018, 19(1):946
  3. Analysis of phenotypic- and Estimated Breeding Values (EBV) to dissect the genetic architecture of complex traits in a Scots pine three-generation pedigree design
    J Theor Biol. 2019, 462:283-292
  4. Non-destructive wood density assessment of Scots pine (Pinus sylvestris L.) using Resistograph and Pilodyn
    PLoS One. 2018,13(9):e0204518
  5. Early selection for resistance to Heterobasidion parviporum in Norway spruce is not likely to adversely affect growth and wood quality traits in late-age performance
  6. Efficiency of using spatial analysis for Norway spruce progeny tests in Sweden
  7. Genomic relationships reveal significant dominance effects for growth in hybrid Eucalyptus
    Plant Sci. 2018, 267:84-93
  8. Genetic analysis of lodgepole pine (Pinus contorta) solid-wood quality traits
    Canadian Journal of Forest Research 2017, 47 (10):1303-1313
  9. Spatial analysis increases efficiency of progeny testing of Chinese fir
    JOURNAL OF FORESTRY RESEARCH 2017, 28 (3):445-452
  10. Estimation of number and size of QTL effects in forest tree traits
    TREE GENETICS & GENOMES, 12 (6), DEC 2016
  11. Patterns of additive genotype-by-environment interaction in tree height of Norway spruce in southern and central Sweden
    TREE GENETICS & GENOMES 2017, 13(1)
  12. Genetic analysis of fiber dimensions and their correlation with stem diameter and solid-wood properties in Norway spruce
    Genetics & Genomes (2016) 12: 123
  13. Inheritance of growth and survival in two 9-year-old, open-pollinated progenies of an advanced breeding population of Chinese firs in southeastern China
    JOURNAL OF FORESTRY RESEARCH 2016, 27(5):1067-1075
  14. Method for accurate fiber length determination from increment cores for large-scale population analyses in Norway spruce
    HOLZFORSCHUNG, 70 (9):829-838; 10.1515/hf-2015-0138 SEP 2016
  15. Performance of Seven Tree Breeding Strategies Under Conditions of Inbreeding Depression
    G3-GENES GENOMES GENETICS 2016, 6(3):529-540
  16. Age trend of heritability, genetic correlation, and efficiency of early selection for wood quality traits in Scots pine
  17. Estimating solid wood properties using Pilodyn and acoustic velocity on standing trees of Norway spruce
    ANNALS OF FOREST SCIENCE, 2015; 72(4):499-508
  18. Measuring stiffness using acoustic tool for Scots pine breeding selection
  19. Characterizing compression wood formed in radiata pine branches
    IAWA Journal 2014, 35(4):385 – 394
  20. Stem damage of lodgepole pine clonal cuttings in relation to wood and fiber traits, acoustic velocity, and spiral grain
  21. Comparison of allelic diversity between native gene resource plantings and selections in open-pollinated progeny test of Pinus radiata D. Don
    SILVAE GENETICA, 2014; 63(5):213-221
  22. Inheritance of growth and solid wood quality traits in a large Norway spruce population tested at two locations in southern Sweden
    Tree Genetics & Genomes, 2014; 10(5):1291-1303
  23. Genetic parameters and genotype-environment interactions of Chinese fir (Cunninghamia lanceolata) in Fujian Province

  24. Single versus subdivided population strategies in breeding against an adverse genetic correlation
    TREE GENETICS & GENOMES, 2014; 10 (3):605-617
  25. High negative genetic correlations between growth traits and wood properties suggest incorporating multiple traits selection including economic weights for the future Scots pine breeding programs
    ANNALS OF FOREST SCIENCE, 2014, 71(4):463-472
  26. Transcriptome profiling of radiata pine branches reveals new insights into reaction wood formation with implications in plant gravitropism
    BMC Genomics. 2013; 14(1):768
  27. Chen D, Zhang X, Kang H, Sun X, Yin S, Du H, Yamanaka N, Gapare W, Wu HX, Liu C
    Phylogeography of Quercus variabilis based on chloroplast DNA sequence in east asia: Multiple glacial refugia and mainland-migrated island populations
    PLoS ONE 2012, 7(10): e47268.
  28. Li X, Wu HX, Southerton SG
    Identification of putative candidate genes for juvenile wood density in Pinus radiata
    Tree Physiol. 2012; 32(8):1046-57
  29. Gapare WJ, Ivković M, Dillon SK, Fiona C, Evans R, Wu HX
    Genetic parameters and provenance variation of Pinus radiata D. Don. 'Eldridge collection' in Australia 2: wood properties
    Tree Genetics and Genomes 2012 Volume 8 (4):895-910
  30. Abrahamsson S, Nilsson JE, Wu H, García-Gil MR, Andersson B
    Inheritance of height growth and autumn cold hardiness based on two generations of full-sib and half-sib families of Pinus sylvestris
    Scandinavian Journal of Forest Research: Available online: 14 Feb 2012
  31. Gapare WJ, Ivković M, Dutkowski GW, Spencer DJ, Buxton P, Wu HX
    Genetic parameters and provenance variation of Pinus radiata D. Don. 'Eldridge collection' in Australia 1: growth and form traits
    Tree Genetics and Genomes  2012, 8(2):391-407
  32. Bian L, Gapare WJ, Ivkovic M, Jefferson P, Wu HX
    Genetic variation between and within ex-situ native-provenance collections of Pinus radiata D. Don planted in Australia and New Zealand
    Silvae Genetica 2011, 60:276-284
  33. Li X, Wu HX, Southerton SG
    Transcriptome profiling of Pinus radiata juvenile wood with contrasting stiffness identifies putative candidate genes involved in microfibril orientation and cell wall mechanics
    BMC Genomics. 2011 Oct 1;12:480
  34. Li XG, Wu HX, Southerton SG
    Transcriptome profiling of wood maturation in Pinus radiata identifies differentially expressed genes with implications in juvenile and mature wood variation
    Gene 2011, 487: 62–71
  35. Wu HX, Sanchez L
    Effect of selection method on genetic correlation and gain in a two-trait selection scheme
    Australian Forestry: 2011 74:36-42
  36. Li W, Li H, Wu H, Chen X-Y
    Use of chromosome walking in discovery of single-nucleotide polymorphism in noncoding regions of a candidate actin gene in Pinus radiata
    Journal of Applied Genetics: 2010 51:275-281
  37. Gapare WJ, Matheson CA, Ivkovic M, Baltunis BS, Wu HX
    Genetic stability of wood density in Pinus radiata D. Don plantation estate across Australia
    Tree Genetics and Genomes: 2010 6:113-125
  38. Baltunis BS, Powell MB, Wu HX
    Genotype by environmental interaction for DBH, wood density, branch angle, branch size, and stem straightness in eight young Pinus radiata trials in Australia
    Silvae Genetica: 2010 59:113-124
  39. Ivkovic M, Wu HX, Kumar S
    Bio-economic modeling as a method for determining economic weights for optimal multiple-trait tree selection
    Silvae Genetica: 2010 59:77-90
  40. Ivcovic M, Baltunis B, Gapare WJ, Elms S, Sasse J. Dutkowski G, Wu HX
    Breeding against Dothistroma needle blight of radiata pine in Australia
    Canadian Journal of Forest Research: 2010, 40:1653-1660
  41. Li XG, Wu HX, Southerton SG
    Seasonal reorganization of the xylem transcriptome at different tree ages reveals novel insights into wood formation in Pinus radiata D.Don
    New Phytologist: 2010 187:764-776
  42. Li XG, Wu HX, Southerton SG
    Comparative genomics of xylem evolution in vascular plants
    BMC Evolutionary Biology: 2010 10:190
  43. Dillon SK, Nolan MF, Li W, Matter P, Wu HX, Southerton SG
    Allelic variation in cell wall candidate genes affects solid wood properties in natural populations and land races of radiata pine
    Genetics: 2010 185:1477-1487
  44. Gapare WJ, Baltunis BS, Ivkovic M, Low CB, Jefferson P, Wu HX
    Performance differences among ex-situ native-provenance collections of Pinus radiata D. Don 1: Potential for infusion into breeding populations in Australia and New Zealand
    Tree Genetics and Genomes: 2010 5:456-465
  45. Baltunis BS, Gapare WG, Wu HX
    Genetic parameters and genotype by environment interaction in radiata pine for growth and wood quality traits in Australia
    Silvae Genetica 2010, 59:113-124
  46. Gapare J, Matheson CA, Ivković M, Baltunis BS, Wu HX
    Genetic stability of wood density in Pinus radiata D. Don plantation estate across Australia
    Tree Genetics & Genomes 2010, 6:113–125
  47. Ivković M, Gapare WJ, Wharton T,  Jovanovic T, Elms S, McRae TA, Wu HX
    Risks affecting breeding objective for radiata pine in Australia
    Australian Forestry 2010, 73:265-278.
  48. Baltunis BS, Wu HX, Dungey HS, Mulli TJ, Brawner JT
    Comparisons of genetic parameters and clonal value predictions from SE varietal trials and seedling base population trials of radiata pine
    Tree Genetics and Genomes 2009, 5:269-278
  49. Zhang Jf, Jiang JM, Zhang ZJ, Shan QH, Chen GC, Wang Y, Xu YH, Wu HX, Abarquez A
    Discussion on role of forest to control agricultural non-point source pollution in Taihu Lake basin-based on source-sink analysis
    Journal of Water Resource and Protection, 2009: 345-350
  50. Li X, Wu HX, Dillon SH, Southerton SG
    Generation and analysis of expressed sequence tags from six developing xylem libraries in Pinus radiata D. Don
    BMC Genomics 2009, 10:41
  51. Gapare, WJ, Baltunis BS, Ivković M, Wu HX
    Genetic correlations among juvenile wood quality and growth traits and optimal selection strategy in Pinus radiata D. Don.
    Annuals of Forest Science 2009, 66:606-614
  52. Ding MM, Tier B, Yan W, Wu HX
    Application of GGE biplot analysis to evaluate genotype (G), environment (E) and GxE interaction on Pinus radiata: a case study
    N.Z.J. For. Sci. 2008 38:132-142
  53. Wu HX, Ivkovich M, Gapare WJ, Matheson AC, Baltunis BS, Powell MB, McRae TA
    Breeding for wood quality and profit in radiata pine: a review of genetic parameters and implication for breeding and deployment
    N.Z.J. For. Sci. 2008, 38:56-87
  54. Gapare WJ, Ivković M, Wu HX
    Genetics of shrinkage in juvenile trees of radiata pine from two test sites in Australia
    Silvae Genetica 2008, 57: 145-151
  55. Matheson AC, Gapare WG, Ilic J, Wu HX
    Inheritance and genetic gain in wood stiffness in radiata pine measured acoustically in standing young trees
    Silvae Genetica 2008, 57:56-64
  56. Ding MM, Tier B, Dutkowski GW, Wu HX
    Multi-environment trial analysis on Pinus radiata: step by step to search "real" GxE interaction
    N.Z.J. For. Sci. 2008, 38:143-159
  57. Ivković M, Gapare WJ, Powell MB, Ilic J, Wu HX
    Prediction of wood stiffness, strength, and shrinkage in juvenile corewood of radiata pine
    Wood Science and Technology 2008, 43:237-257
  58. Li W, Li H, Chen XY, Wu HX
    Single nucleotide polymorphism discovery of Pinus radiata with chromosome walking PCR method
    Frontiers of Forestry in China 2008, 3: 352-356
  59. Wu HX, Powell MB, Yang JL, Ivković M, McRae TA
    Efficiency of early selection for rotation-aged wood quality traits in radiata pine
    Annals of Forest Science 2007, 64:1-9
  60. Gapare WJ, Hathorn A, Kain AD, Matheson AC, Wu HX
    Inheritance of spiral grain in the juvenile core of Pinus radiate
    Can. J. For. Res. 2007, 37: 116-127
  61. Ivkovich M, Wu HX, Spencer DJ, McRae TA
    Modelling the effects of tree traits on radiata pine structural timber production
    Australian Forestry 2007, 70:173-184
  62. Baltunis BS, Wu HX, Powell MB
    Inheritance of density, microfibril angle, and modulus of elasticity in juvenile wood of Pinus radiate
    Can. J. For. Res. 2007, 37:2164-2174
  63. Ivković M, Wu HX, McRae TA, Powell MB
    Developing breeding objectives for radiata pine structural wood production. I. Bioeconomic model and economic weights
    Can. J. For. Res. 2006, 36:2920-2931
  64. Ivković M, Wu HX, McRae TA, Matheson AC
    Developing breeding objectives for radiata pine structural wood production. II. Sensitivity analyses
    Can. J. For. Res. 2006, 36:2932-2942
  65. Li L, Wu HX
    Efficiency of early selection for rotation-aged growth and wood density traits in Pinus radiate
    Can. J. For. Res. 2005, 35:2019-2029
  66. Gapare WJ, Wu HX, Abarquez A
    Genetic control in the time of transition from juvenile wood to mature wood in Pinus radiata D. Don
    Annals of Forest Science 2006, 63: 871-878
  67. Wu HX, Matheson AC
    Genotype by environment interaction in an Australia-wide radiata pine diallel mating experiment: Implications for regionalized breeding
    Forest Science 2005, 51:29-40
  68. Wu HX, Matheson AC
    General and specific combining ability for partial diallels of radiata pine: Implications for utility of SCA in breeding and deployment populations
    Theor. and Appl. Genet. 2004, 108:1503-1512
  69. Wu HX, Ying CC
    Geographic patterns of local optimality in natural populations of lodgepole pine
    Forest Ecology and Management 2004, 194:177-198
  70. Wu HX, Owen JV, Abarquez A, Matheson AC
    Inbreeding in Pinus radiata: V. Inbreeding effect on fecundity
    Silvae Genetica 2004, 53:80-87
  71. Wu HX, Ying CC, Ju H-B
    Predicting site productivity and pest hazard in lodgepole pine using biogeoclimatic system and geographic variables in British Columbia
    Annals of Forest Science 2004, 61:1-12
  72. Glaubitz JC, Wu HX, Moran GF
    Impacts of silviculture on genetic diversity in the native forest species Eucalyptus sieberi
    Conservation Genetics 2003, 4:187-195
  73. Kuma S, Wu HX
    Reciprocal and maternal effects on growth and form traits in radiata pine in New Zealand
    Silvae Genetica 2003, 52:71-74
  74. Matheson AC, Wu HX, Spencer D
    Inbreeding in Pinus radiata: III. Effect of inbreeding on age-age correlation and early selection efficiency
    Silvae Genetica 2002, 51:115-122
  75. Wu HX, Matheson AC, Abarquez A
    Inbreeding in Pinus radiata: VI. Inbreeding effect on wood density
    Annals of Forest Science 2002, 59:557-562
  76. Wu HX
    Study of early selection in tree breeding: 4. Efficiency of marker-aided early selection
    Silvae Genetica 2002, 51:261-269
  77. Wu HX, Matheson AC
    Analysis of half-diallel mating design with missing crosses: theory and SAS program for testing and estimating GCA and SCA variance components
    Silvae Genetica 2001, 50:265-271
  78. Wu HX, Matheson AC
    Reciprocal, maternal, non-maternal effects in radiata pine diallel mating experiment on four Australia sites
    Forest Genetics 2001, 8:205-212
  79. Wu HX, Ying CC
    Variation in reaction norm of natural lodgepole pine populations
    Theor. and Appl. Genet. 2001, 103:331-345
  80. Wu HX, Burdon RD
    Accounting for breeding values, heterogenous variances and maternal effects in estimating inbreeding depression for individual pedigree
    Forest Genetics 2000, 7:267-275
  81. Wu HX, Matheson AC
    Analysis of half-diallel mating design with missing crosses: theory and SAS program for testing and estimating GCA and SCA fixed effects
    Silvae Genetica 2000, 49:130-137
  82. Wu HX, Yeh FC, Dancik BP, Pharis R, Dhir NK
    Study of early selection in tree breeding: 3. A case study using early information to enhance selection efficiency in later trait in lodgepole pine
    Silvae Genetica 2000, 49:152-158
  83. Wu HX
    Study of early selection in tree breeding: 2. Advantage of early selection through shortening of breeding cycle
    Silvae Genetica 1999, 48: 79-83
  84. Wu HX, Matheson AC, Spencer D
    Inbreeding in Pinus radiata I. The effect of inbreeding on growth, survival and variance
    Theor. and Appl. Genet. 1998, 97:1256-1268
  85. Wu HX, Matheson AC, Spencer D
    Inbreeding in Pinus radiata II. Time trend of inbreeding depression with tree age and effects on growth curve
    N. Z. J. For. Sci. 1998, 28:123-139
  86. Wu HX, Ying CC
    Stability to western gall rust and needle cast resistance in lodgepole pine
    Can. J. For. Res. 1998, 28:439-449
  87. Wu HX
    Study of early selection in tree breeding: 1. Advantage of early selection through increase of selection intensity and reduction of field test size
    Silvae Genetica1998, 47:146-155
  88. Wu HX, Yeh FC
    Genetic effect on biomass partition and breeding for tree architecture in Pinus contorta ssp. latifolia
    Forest Genetics 1997, 4:123-130
  89. Wu HX, Ying CC
    Genetic parameters and selection efficiencies in resistance to western gall rust, stalactiform blister rust, needle cast and sequoia pitch month in lodgepole pine
    Forest Science 1997, 43:571-581
  90. Wu HX, Yeh FC, Dhir NK, Pharis RP, Dancik BP
    Genotype by environment interaction and genetic correlation of greenhouse and field performance in Pinus contorta ssp. Latifolia
    Silvae Genetica 1997, 46:170-175
  91. Wu HX, Ying CC, Muir JA
    Effect of geographic variation and jack pine introgression on disease and insect resistance in lodgepole pine
    Can. J. For. Res. 1996, 26:711-726
  92. Wu HX, Yeh FC, Dancik BP, Pharis RP, Dhir NK, Isreal BJ
    Genetic parameters of greenhouse growth and performance of 2-year Pinus contorta subsp. latifolia.
    Scand. J. For. Res. 1995, 10:12-21