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| 2. |
- Eklöf, Helena, 1989-
(författare)
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Genetic diversity and differentiation in natural and managed stands of Norway spruce (Picea abies)
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Being one of Sweden’s most important tree species, both as a keystone species and for the forest industry, it is important that we keep our stands of Norway spruce (Picea abies (L.) Karst.) as healthy as possible. With an unclear starting point of existing genetic diversity in natural forests we need to both evaluate what levels of natural diversity we have to begin with and how modern forestry practices might affect this. Previous studies have used relatively few markers to study this or similar situation before. We proved that both capture probes and genotyping by sequencing (GBS) show similar results in common diversity measurements and offers many SNPs, although capture probes showed slightly more diversity in the results, we choose to use PoolSeq and GBS together to examine a large number of planted and natural stands of Norwegian spruce in northern Sweden. In line with previous results on the subject we did not find any large differences between our young, planted forests and our old forests, suggesting that today’s re-planting methods have not affected the general diversity in different stands. However, we did find a difference in the variance of our summary statistics on a stand level between planted and old stands, an indicator that there is a possibility that forestry can cause long-term effects. This becomes even more important in the light of possible clonal deployment of Norway spruce. I believe that more research is needed over both larger geographical areas and with a focus on within stand variation. Using mitochondrial and chloroplast DNA to discern finer details of spatial distribution within stands and looking closer at the genotypic diversity within natural and planted stands. An effort should also be put into examine how these possible differences are affecting the rest of the ecosystem, living with and among Norway spruce.
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| 3. |
- 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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| 4. |
- Huttunen, Piritta, et al.
(författare)
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Leaf trichome production and responses to defoliation and drought in Arabidopsis lyrata (Brassicaceae)
- 2010
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Ingår i: Annales Botanici Fennici. - Helsinki : Finnish Zoological and Botanical Publishing Board. - 0003-3847 .- 1797-2442. ; 47:3, s. 199-207
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Tidskriftsartikel (refereegranskat)abstract
- Leaf trichomes can protect plants against herbivory and drought, but can be costly to produce. Theory suggests that selection for reduced costs of resistance may result in the evolution of inducible defences. We quantified variation in tolerance to drought and defoliation, and tested the hypotheses that (a) tolerance is associated with cost, (b) leaf trichome production increases tolerance to drought, and (c) trichome production is increased in response to defoliation and drought stress in Arabidopsis lyrata (Brassicaceae). Eight maternal half-sib families were exposed to two watering regimes and four defoliation treatments in a factorial design. Tolerance to drought varied among families and was inversely related to leaf size, but was not related to trichome density. Family mean performance in the low-watering treatment tended to correlate negatively with that in the control treatment. Trichome production was not induced by defoliation or drought stress. The results suggest that there is genetic variation in tolerance to drought in the study population, that tolerance to drought is associated with a cost, and that trichome production does not increase tolerance to drought in A. lyrata.
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| 5. |
- Kivimäki, Maarit, et al.
(författare)
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Gene, phenotype and function : GLABROUS1 and resistance to herbivory in natural populations of Arabidopsis lyrata
- 2007
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Ingår i: Molecular Ecology. - 0962-1083 .- 1365-294X. ; 16:2, s. 453-462
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Tidskriftsartikel (refereegranskat)abstract
- The molecular genetic basis of adaptive variation is of fundamental importance for evolutionary dynamics, but is still poorly known. Only in very few cases has the relationship between genetic variation at the molecular level, phenotype and function been established in natural populations. We examined the functional significance and genetic basis of a polymorphism in production of leaf hairs, trichomes, in the perennial herb Arabidopsis lyrata. Earlier studies suggested that trichome production is subject to divergent selection. Here we show that the production of trichomes is correlated with reduced damage from insect herbivores in natural populations, and using statistical methods developed for medical genetics we document an association between loss of trichome production and mutations in the regulatory gene GLABROUS1. Sequence data suggest that independent mutations in this regulatory gene have provided the basis for parallel evolution of reduced resistance to insect herbivores in different populations of A. lyrata and in the closely related Arabidopsis thaliana. The results show that candidate genes identified in model organisms provide a valuable starting point for analysis of the genetic basis of phenotypic variation in natural populations.
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| 6. |
- Kärkkäinen, Katri, et al.
(författare)
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Population structure in Arabidopsis lyrata : evidence for divergent selection on trichome production.
- 2004
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Ingår i: Evolution. - : The Society for the Study of Evolution. - 0014-3820 .- 1558-5646. ; 58:12, s. 2831-2836
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Tidskriftsartikel (refereegranskat)abstract
- Leaf trichomes may serve several biological functions including protection against herbivores, drought, and UV radiation; and their adaptive value can be expected to vary among environments. The perennial, self-incompatible herb Arabidopsis lyrata is polymorphic for trichome production, and occurs in a glabrous and a trichome-producing form. Controlled crosses indicate that the polymorphism is governed by a single gene, with trichome production being dominant. We examined the hypothesis that trichome production is subject to divergent selection (i.e., directional selection favoring different phenotypes in different populations) by comparing patterns of variation at the locus coding for glabrousness and at eight putatively neutral isozyme loci in Swedish populations of A. lyrata. The genetic diversity (H-e) and allele number at isozyme loci tended to increase with population size and decreased with latitude of origin, whereas genetic diversity at the locus coding for glabrousness did not vary with population size and increased with latitude of origin. The degree of genetic differentiation at the glabrousness locus was much higher than that at isozyme loci. Genetic identity at isozyme loci was negatively related to geographic distance, suggesting isolation by distance. In contrast, there was no significant correlation between genetic identity at the glabrousness locus and at isozyme loci. The results are consistent with the hypothesis that divergent selection contributes to population differentiation in trichome production in A. lyrata.
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| 7. |
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| 8. |
- Savolainen, Outi, et al.
(författare)
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Adaptation of forest trees to climate change
- 2007
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Ingår i: Climate change and forest genetic diversity. - Rome : Bioversity International. - 9789290437499 ; , s. 19-30
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Konferensbidrag (refereegranskat)
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