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- 2017
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Ingår i: Physical Review D. - 2470-0010 .- 2470-0029. ; 96:2
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Tidskriftsartikel (refereegranskat)
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- Niemi, MEK, et al.
(författare)
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- 2021
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swepub:Mat__t
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- Kanai, M, et al.
(författare)
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- 2023
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swepub:Mat__t
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- Hayatgheibi, Haleh, et al.
(författare)
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Implications of accounting for marker-based population structure in the quantitative genetic evaluation of genetic parameters related to growth and wood properties in Norway spruce
- 2024
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Ingår i: BMC Genomic Data. - : BioMed Central Ltd. - 2730-6844. ; 25:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Forest geneticists typically use provenances to account for population differences in their improvement schemes; however, the historical records of the imported materials might not be very precise or well-aligned with the genetic clusters derived from advanced molecular techniques. The main objective of this study was to assess the impact of marker-based population structure on genetic parameter estimates related to growth and wood properties and their trade-offs in Norway spruce, by either incorporating it as a fixed effect (model-A) or excluding it entirely from the analysis (model-B). Results: Our results indicate that models incorporating population structure significantly reduce estimates of additive genetic variance, resulting in substantial reduction of narrow-sense heritability. However, these models considerably improve prediction accuracies. This was particularly significant for growth and solid-wood properties, which showed to have the highest population genetic differentiation (QST) among the studied traits. Additionally, although the pattern of correlations remained similar across the models, their magnitude was slightly lower for models that included population structure as a fixed effect. This suggests that selection, consistently performed within populations, might be less affected by unfavourable genetic correlations compared to mass selection conducted without pedigree restrictions. Conclusion: We conclude that the results of models properly accounting for population structure are more accurate and less biased compared to those neglecting this effect. This might have practical implications for breeders and forest managers where, decisions based on imprecise selections can pose a high risk to economic efficiency.
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- Tan, Biyue, 1986-
(författare)
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Genomic selection and genome-wide association studies to dissect quantitative traits in forest trees
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The convergence of quantitative genetics of complex traits with genomic technologies is quickly becoming an innovative approach to explore fundamental genetic questions and also have practical consequences for implementations in tree breeding. In this thesis, I used genomic selection and genome-wide association studies (GWAS) to dissect the genetic basis of quantitative traits, i.e. growth, phenology and wood property traits. I also assessed the importance of dominance and epistatic effects in hybrid Eucalyptus. Both dominance and epistasis are important in hybrids, as they are the likely contributing to the genetic basis of heterosis. To successfully implement genomic selection models, several important factors have to be considered. I found that for a good model establishment, both the size and composition of the training population, as well as the number of SNPs to be important considered. Based on the optimal models, additive, dominance and epistasis genetic effects of growth and wood traits have been estimated to evaluate genetic parameters and how these influence the prediction accuracy, which can be used in selecting elite breeding individuals or clones. I also addressed the advantage of genotyping-based analyses by showing that we could accurately correct pedigree information errors. More importantly, genotyping-based analyses capture both Mendelian segregation variation within full-sib families and cryptic genetic links through unknown common ancestors, which are not available from traditional pedigree data. GWAS were used to analyse growth and phenology related traits. Using a single-trait GWAS method, we identified a region strongly associated with the timing of bud set in Populus tremula, a trait with high heritability. For the growth related traits, we found that a multi-traits GWAS approach was more powerful than single-trait analyses as it identified more associated SNPs in hybrid Eucalyptus. Moreover, many more novel associated SNPs were identified from considering over-dominance effects in the GWAS analyses. After annotating the associated SNPs I show that these functional candidate genes were related to growth and responding to abiotic and biotic stress. In summary, the results of genomic selection and GWAS provided a deeper understanding of the genetic backgrounds of quantitative traits in forest trees.
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- Wu, Harry X.
(författare)
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Benefits and risks of using clones in forestry - a review
- 2019
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Ingår i: Scandinavian Journal of Forest Research. - : Taylor & Francis. - 0282-7581 .- 1651-1891. ; 34:5, s. 352-359
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Forskningsöversikt (refereegranskat)abstract
- The use of vegetative propagation in forestry has a long history. In this chapter of special issue, the genetic gain from clonal forestry relative to family forestry is reviewed. Both theoretical studies and experimental data from progeny and clonal trials indicate that extra genetic gain (5-25%) is possible in conifer from clone testing and deployment relative to deployment of family forestry, effectively doubling that achievable from family forestry within the same generation. There are three perceived risks from using clones in forestry: (1) risk of plantation failure, (2) risk of diversity loss at the forest and landscape levels, and (3) risk associated with success rate of vegetative (or SE) propagation. Three theoretical models are reviewed and described to assess risk and to determine the number of clones required to mitigate these risks. All studies support that a "safe" number of clones is between 5 and 30. Genetic gains and experiences are reported for individual species, particularly in conifers, as well as in Eucalypts. The combination of genomic selection with somatic embryogenesis has the potential to accelerate the development of clonal forestry by shortening clonal testing or omitting long-term clonal testing completely.
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